# Lecture Notes on Programming Languages

Size: px
Start display at page:

Transcription

1 Lecture Notes on Programming Languages 37 Lecture 04: Data Types and Variables All programming languages provide data types. A data type describes a set of data values and a set of predefined operations that are applicable to the data items belonging to the set. This lecture contains: Primitive Data Types Variables Programmer-defined Data Types Copyright by All rights reserved. No part of this document may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, or otherwise, without prior written permission of the author.

2 Primitive Data Types A data type describes a set of data values and a set of predefined operations that are applicable to the data items belonging to the set. A primitive data type is a data type that is not defined in terms of other data types. Primitive data types are the building blocks for data representation in a programming language. Most programming languages support the following primitive data types: integer, real number, Boolean, character, string Integer The integer data type includes the set of positive and negative whole numbers. Implementations range from 4 bytes to 8 bytes. Some languages have variations of the integer type. For example, Java implements the following variations: byte, short, int, and long. C++ implements the following variations: short, int, long, and unsigned. Note: Most computers implement negative integers as 2 s compliment or 1 s compliment Real Number You will recall from your elementary mathematics that the set of real numbers includes all (non-complex) numbers. In several languages (including C-based languages), real numbers are implemented as floatingpoint numbers and double precision floating-point numbers. Business-oriented languages such as COBOL, C#, and SQL (structured query language) have a decimal data type. SQL also has a number data type, which is essentially a real number. The language Pascal has a real data type Boolean A Boolean data type allows for two possible values: true or false. This data type was first introduced in ALGOL 60, and has since been adopted by most programming languages. Earlier versions of C did not have a Boolean data type, but allowed numeric expressions to be treated as though they were Boolean. This was subsequently revised in C++ to incorporate a truly Boolean data type. Even though technically speaking, only a bit is required to store Boolean values, for practical reasons, a byte is often used Character The character data type relates to the representation of alphanumeric data. Traditionally, the coding systems were EBCDIC and ASCII. There is also the ISO coding system. These are all 8-bi8t systems. In more recent times, we have seen the introduction of the 16-bit Unicode system as implemented in Java, C#, and JavaScript.

3 Strings A string is a sequence of characters. Some languages (e.g. Pascal) implement strings as primitive data types. Others (e.g. C++ and Java) implement strings as advanced data types. Some languages implement variable length strings (e.g. Java); others provide the flexibility of implementing fixed or variable length strings (e.g. Pascal and C++). 4.2 Variables As you are aware, a variable is a name or identifier used to specify a data item. During the translation process, variables are translated to memory locations at execution-time, hence, the use of the symbol table (review lecture 3). The generic term identifier is used to refer to variables, labels, or subprograms. To be clear, we will be explicit about the elements used. How identifiers are treated in a programming language is an issue that must be resolved early in the design of the language Variable Naming In most languages, the convention is to have identifiers beginning with a letter, followed by a string of characters, including the underscore. Hyphens are usually not allowed, since they may be confused with the minus sign (-). In some languages, external names are restricted to a specific length (e.g. C and RPG-400). A few languages also have length restrictions on internal identifiers (e.g. RPG-400). Languages such as Java, C#, Ada, and Pascal have no limit on identifier names. In C-based languages, the so-called camel notation has replaced the more traditional notation. The camel notation begins with an identifier name with a lowercase letter, and capitalizes the first letter subsequent words in a multi-word name (e.g. thebirthdate). The more traditional approach is to capitalize the first letter of each word in the identifier (e.g. TheBirthDate). Neither convention is enforced by syntax, so observance is left to the discretion of the programmer (and rightly so) Reserve Words Every language has reserve words. These are special words that can only be used for their intended purpose; they cannot be used as identifiers. Reserve words include primitive data types and qualifiers Variable Declaration Some languages require variable declaration before usage. The declaration alerts the compiler or interpreter of the identifier, and allows for easy loading of the symbol table. Languages such as Pascal and Oracle s PL-SQL represent the strictest form of this strategy.

4 Variable Declaration (continued) Some languages do not require variable declaration prior to usage. Two examples of such languages are Basic and FoxPro. For these languages, constructing and maintaining the symbol table is more complicated the ability to report errors relating to the use of variables is more difficult. C-based languages provide a compromise, where a variable can be declared at the point where it is first introduced. However, the conventional wisdom is that it is a good habit to declare variables prior to their usage. The syntax of Pascal-based languages (including Pascal and Oracle PL-SQL) require variable the variablename prior to the data type of the variable; C-based languages require the data type prior to the variablename. Figure 4.1 illustrates Figure 4.1: Illustrating Variable Declaration in Pascal versus C++ and Java Pascal Variable Declaration follows. Note, this is how a Pascal comment is made:} Var MyName: String; // Java declaration follows. Note, this is how a comment is made is C-based languages: String MyName; // C++ declaration follows. Note, this is how a comment is made is C-based languages: string MyName; char* MyName; // An alternate way of defining a C++ string char MyName[n]; // An alternate way of defining a C++ string, assuming that n is previously defined Binding of Attributes to Variables There are two approaches to binding, as discussed below: Static Binding: Binding of attributes to variables occurs before runtime. Dynamic Binding: Binding of attributes to variables occurs at runtime. Dynamic binding (also called late binding) is considered more flexible and efficient than static binding (also called early binding) Strong Typing A strongly types language is a language in which each variable-name has a single data type associated with it, and this is known at compilation time. Strongly typed languages tend to detect type violations rather early in the translation process. Pascal and Ada are strongly typed; C, C++, and Fortran are not. Java and C#, despite being C-based, are strongly typed; however, they facilitate type conversion through promotion or casting.

5 Data Conversion Some languages allow for data type conversion implicitly from lower range to higher range (e.g. integer to real), and explicitly via casting. This is so in C-based languages. Other languages such as Pascal do not allow for type conversion. In the case of Python and Visual Basic, explicit data conversion functions are provided Variable Scope The scope of a variable is the range of statements in which it is visible. Of interest is the scope rules that the language implements. The conventional wisdom is that a variable scope is confined to the programming block in which it was defined. This is referred to as static scoping. Languages such as APL, SNOBOL4, LISP, Common LISP, and Perl support dynamic scoping, where the scope of the variable may change at runtime. This is quite problematic, and can significantly affect the performance of the program, if care is not taken. On the surface, C and C++ appear to support static scoping. However, these languages do allow indirect access of variables outside of their scope via reference parameters and pointers Program Blocks How does a programming language handle blocking? C-based languages use the left and right curly braces (}). Ada, Pascal, and PL-SQL use the keywords begin and end Named Constants A constant is a variable that is bound to one value for the duration of the program execution. Named constants are useful in improving the readability of the program. Pascal, C, and C++ allow for declaration of constants via the const keyword. Java requires the use of the final keyword. Figure 4.2 provides some examples. Figure 4.2: Illustrating Constant Declaration in Pascal, C++, and Java Pascal constant declaration follows.} Const PI = 3.142; // Java constant declaration follows. double final PI = 3.142; // C++ constant declaration follows const double PI = 3.142;

6 Programmer-defined Data Types A programmer-defined data type (also called abstract data type) is a data type that the programmer defines, using primitive data types and/or other programmer-defined data types as building blocks. Some languages are more flexible than others in this regard. Among these data types are the following: enumerated types, sub-range types, arrays, records, unions, pointers, etc Enumerated Types Some languages allow for definition of enumerated data types. An enumeration is a list of allowed values for data items defined on this data type. Enumerated types are suited for situations where a finite list of legal values is required. This is supported in languages such as C++, Java, Pascal, and Ada. Figure 4.3 illustrates. Figure 4.3: Illustrating Enumerated Types in Pascal, C++, and Java Pascal enumerated type definition for days of the week follows.} Type DaysOfWeek = (SUN, MON, TUE, WED, THU, FRI, SAT); // Java enumerated type definition for days of the week follows enum DaysOfWeek SUN, MON, TUE, WED, THU, FRI, SAT}; // C++ enumerated type definition for days of the week follows enum DaysOfWeek SUN, MON, TUE, WED, THU, FRI, SAT}; Sub-range Types A sub-range is a continuous stream of values between two stated limits. Pascal and Ada support this data type. Below is a Pascal example. Pascal declaration of a sub-range follows} Type Month = ; Having defined the sub-range, we can declare variables of it} Var mymonth: Month; Arrays An array is a finite list of data items belonging to a particular base type. Most languages support arrays, some more efficiently than others. Most languages require that the dimension(s) of the array be known before its declaration. This is true for Pascal, C, C++, RPG-400, etc. However, C++ allows the programmer to resize the array by allocating more memory for it.

7 Arrays (continued) Java allows the programmer to declare the array without specifying its precise dimension(s). When the actual size is known, the array is then created and its size specified. Like C++, the array size can be modified. Java also supports heterogeneous arrays by allowing the programmer to declare and manipulate an array of the Object class. Languages such as SAL (Scalable Application Language) and C99 support variable-length arrays. Figure 4.4 shows array declarations in Pascal, Java, and C++

8 44 Figure 4.4: Illustrating Array Declarations in Pascal, C++, and Java Figure 4.4a: Pascal BNF Definition of an Array ArrayDefinition ::= Arrray [<Sub-range>] of <DataType> (* Note, the square bracket is a required part of the syntax *) (* Example follows *) Type SaleList = Array[1..12] of Real; Var Sale: SaleList; (* Alternate definition follows *) Var Sale: Array[1.. 12] of Real; (*Alternate definition follows *) Type Month = ; SaleList = Array[Month] of Real; Var Sale: SaleList; Figure 4.4b: Java BNF Definition of an Array ArrayDefinition ::= <DataType>[ ] <ArrayName>; // Note, the square bracket is a required part of the syntax // Example follows double [ ] Sale; int n; // The array is declared Sale = new double[n]; // The array is being created, assuming n has a non-zero positive value Figure 4.4c: C++ BNF Definition of an Array ArrayDefinition ::= <DataType> <ArrayName> [<Length>]; // Example follows int n; double [n] Sale; // Note, in some implementations, n has to be an integer constant // Alternate example follows typedef double SaleList[12]; // The array is first defined as a data type SaleList Sale;

9 Records A record is an aggregation of related data items, possibly of different data types. The term used for record varies with different languages: Pascal, COBOL, and Ada use the term record RPG-400 implements records as data structures C and C++ implements records as structures C++ and Java implements records as classes Figure 4.5 shows record declarations in Pascal, Java, and C++, while figure 4.6 shows how you could define an array of records in each language. Figure 4.5: Illustrating Record Declarations in Pascal, C++, and Java Figure 4.5a: Pascal BNF Definition of a Record RecordDefinition ::= Type <RecordName> = Record <VariableDeclaration>; <VariableDeclaration>;} (*Zero or more data items *) End; (* Example follows *) Type StudentRecord = Record ID_Number: Integer; LastName: String; FirstName: Major: String; GPA: String; Real; End; Var CurrentStud: StudentRecord;

10 46 Figure 4.5: Illustrating Record Declarations in Pascal, C++, and Java (continued) Figure 4.5b: C++ BNF Definition of a Record StructureDefinition ::= struct [<StructureName>] <VariableDeclaration>; *<VariableDeclaration>; // Zero or more data items }[*<VariableName>] ; // Example follows typedef char* String; struct StudentRecord int ID_Number; String LastName; String FirstName; String Major; double GPA; }; // StudentRecord CurrentStud; Figure 4.5c: Java BNF Definition of a Record ClassDefinition ::= public private protected class <ClassName> <VariableDeclaration>; *<VariableDeclaration>; // Zero or more data items public private protected class <ClassName> ([<ParameterList>]) // Constructor *<Statement>; } *<MethodDefinition> // Zero or more methods } // Example follows public class StudentRecord int ID_Number; String LastName, FirstName, Major; double GPA; public class StudentRecord ( ) // Constructor }; // Other methods }; // StudentRecord CurrentStud;

11 47 Figure 4.6: Illustrating Array of Records in Pascal, C++, and Java Figure 4.6a: Pascal Array of Student Records Assuming the declarations of figure 4.5a} Type StudentList = Array [1.. 20] of StudentRecord; Var ThisList: StudentList; Figure 4.6b: C++ Array of Student Records //Assuming the declarations of figure 4.5b typedef StudentRecord StudentList[20]; StudentList ThisList; Figure 4.6c: Java Array of Student Records //Assuming the declarations of figure 4.5c StudentRecord [ ] ThisList; ThisList = new StudentRecord[20]; Unions A union is a record-like structure that stores alternate definitions for certain data items. An item from the union can be referenced from the body of the program by an alternate name. Both Ada and C++ support unions Pointers A pointer is a data type that allows variables defined on it to be references to memory locations. Pointers are useful in implementing dynamic lists, and are for more efficient than static arrays. Languages such as Pascal, C, and C++ support pointers by requiring explicit pointer declarations. Java implicitly supports pointers by simply implementing all objects as reference variables (that reference memory locations). Java provides additional flexibility by allowing the programmer to define and manipulate a list (static or dynamic) of instances of the Object class, thus facilitating a potentially heterogeneous list. By way of illustration, suppose that we desire to construct a dynamic list of student records. The best way to do this in Pascal is via a linked list of student records. The best way to do it in Java is via a linked list, vector, or array-list of student objects (array-list and vectors are essentially dynamic arrays). C++ provides the most flexibility: you could achieve this list in C++ via a pointer to student records, a vector of student records, a linked list of student records, or a linked list of student objects (using a class but possibly two).

12 Pointers (continued) For the purpose of comparison, figure 4.7 illustrates how this dynamic list of student records could be done via the linked list approach in Pascal, C++, and Java. Figure 4.7: Illustrating Pointer Declarations in Pascal, C++, and Java Figure 4.7a: Pascal BNF Definition of a Pointer and Construction of Linked List PointerDefinition ::= Type <PointerName> = ^<DataType>; (* Example of a linked list of student records follows *) Type StudentL = ^StudentRec; StudentRec = Record ID_Number: Integer; LastName: String; FirstName: String; Major: String; GPA: Real; Next: StudentL; Var End; First, Last: StudentL; Figure 4.7b: C++ BNF Definition of a Pointer and Construction of Linked List PointerDefinition ::= <DataType> * // Example of a linked list of student records typedef char* String; struct StudentRec int ID_Number; String LastName; String FirstName; String Major; double GPA; }; struct StudentL StudentRec myrec; StudentL* Next; }; // StudentL First, Last; PointerDefinition ::= <DataType> * // Alternate example of a linked list of student records typedef char* String; struct StudentL int ID_Number; String LastName; String FirstName; String Major; double GPA; StudentL* Next; }; // StudentL First, Last;

13 49 Figure 4.7: Illustrating Pointer Declarations in Pascal, C++, and Java (continued) Figure 4.7c: Java BNF Definition of a Pointer and Construction of Linked List public class StudentRec int ID_Number; String LastName, FirstName, Major; double GPA; public class StudentRec ( ) // Constructor }; }; // Other methods to input, modify, and format information for output respectively public class StudentNode StudentRec Info; StudentNode Next; public class StudentNode ( ) // Constructor }; }; // Other methods to input, modify, and format information for output respectively public class StudentL StudentNode First, Last int Length; } // Notice the indirect approach required in Java as opposed to Pascal and C Other Advanced Data Types There are several other abstract data types (ADTs) that programmers often wish to define and manipulate. The previous subsection mentioned array-lists, vectors, and linked lists. These three data types fall in this category. Other commonly used advanced data types include sets, stacks, queues, trees, and graphs. Programming languages that are to be used in rigorous programming scenarios (particularly in scientific and/or business environments) should support these features. Languages such as Pascal, C, C++, Java, C#, and Ada support these features or their equivalents. Of this group, Java and C++ are particularly impressive in their provision of flexibility with respect to these ADTs (albeit in very different ways).

### Lecture Notes on Programming Languages

Lecture Notes on Programming Languages 65 Lecture 07: Subprograms Subprograms are the building blocks for structuring your program into readable components that are easy to follow. Most programming languages

### Introduction. Primitive Data Types: Integer. Primitive Data Types. ICOM 4036 Programming Languages

ICOM 4036 Programming Languages Primitive Data Types Character String Types User-Defined Ordinal Types Array Types Associative Arrays Record Types Union Types Pointer and Reference Types Data Types This

### Lecture Notes on Programming Languages

Lecture Notes on Programming Languages 85 Lecture 09: Support for Object-Oriented Programming This lecture discusses how programming languages support object-oriented programming. Topics to be covered

### Introduction Primitive Data Types Character String Types User-Defined Ordinal Types Array Types. Record Types. Pointer and Reference Types

Chapter 6 Topics WEEK E FOUR Data Types Introduction Primitive Data Types Character String Types User-Defined Ordinal Types Array Types Associative Arrays Record Types Union Types Pointer and Reference

### Chapter 6. Data Types

Chapter 6 Data Types Introduction A data type defines a collection of data objects and a set of predefined operations on those objects A descriptor is the collection of the attributes of a variable Copyright

### Chapter 6 part 1. Data Types. (updated based on 11th edition) ISBN

Chapter 6 part 1 Data Types (updated based on 11th edition) ISBN 0-321 49362-1 Chapter 6 Topics Introduction Primitive Data Types Character String Types User-Defined Ordinal Types Array Types Associative

### Question No: 1 ( Marks: 1 ) - Please choose one One difference LISP and PROLOG is. AI Puzzle Game All f the given

MUHAMMAD FAISAL MIT 4 th Semester Al-Barq Campus (VGJW01) Gujranwala faisalgrw123@gmail.com MEGA File Solved MCQ s For Final TERM EXAMS CS508- Modern Programming Languages Question No: 1 ( Marks: 1 ) -

### COSC252: Programming Languages: Basic Semantics: Data Types. Jeremy Bolton, PhD Asst Teaching Professor

COSC252: Programming Languages: Basic Semantics: Data Types Jeremy Bolton, PhD Asst Teaching Professor Copyright 2015 Pearson. All rights reserved. Common Types and Design Concerns Primitive Data Types

### Data Types. (with Examples In Haskell) COMP 524: Programming Languages Srinivas Krishnan March 22, 2011

Data Types (with Examples In Haskell) COMP 524: Programming Languages Srinivas Krishnan March 22, 2011 Based in part on slides and notes by Bjoern 1 Brandenburg, S. Olivier and A. Block. 1 Data Types Hardware-level:

### Chapter 6. Data Types ISBN

Chapter 6 Data Types ISBN 0-321 49362-1 Chapter 6 Topics Introduction Primitive Data Types Character String Types User-Defined Ordinal Types Array Types Associative Arrays Record Types Union Types Pointer

### Data Types. Every program uses data, either explicitly or implicitly to arrive at a result.

Every program uses data, either explicitly or implicitly to arrive at a result. Data in a program is collected into data structures, and is manipulated by algorithms. Algorithms + Data Structures = Programs

### STUDY NOTES UNIT 1 - INTRODUCTION TO OBJECT ORIENTED PROGRAMMING

OBJECT ORIENTED PROGRAMMING STUDY NOTES UNIT 1 - INTRODUCTION TO OBJECT ORIENTED PROGRAMMING 1. Object Oriented Programming Paradigms 2. Comparison of Programming Paradigms 3. Basic Object Oriented Programming

### Lecture 12: Data Types (and Some Leftover ML)

Lecture 12: Data Types (and Some Leftover ML) COMP 524 Programming Language Concepts Stephen Olivier March 3, 2009 Based on slides by A. Block, notes by N. Fisher, F. Hernandez-Campos, and D. Stotts Goals

### CSC 533: Organization of Programming Languages. Spring 2005

CSC 533: Organization of Programming Languages Spring 2005 Language features and issues variables & bindings data types primitive complex/structured expressions & assignments control structures subprograms

### Features of C. Portable Procedural / Modular Structured Language Statically typed Middle level language

1 History C is a general-purpose, high-level language that was originally developed by Dennis M. Ritchie to develop the UNIX operating system at Bell Labs. C was originally first implemented on the DEC

### Programming Languages, Summary CSC419; Odelia Schwartz

Programming Languages, Summary CSC419; Odelia Schwartz Chapter 1 Topics Reasons for Studying Concepts of Programming Languages Programming Domains Language Evaluation Criteria Influences on Language Design

### Chapter 5 Names, Binding, Type Checking and Scopes

Chapter 5 Names, Binding, Type Checking and Scopes Names - We discuss all user-defined names here - Design issues for names: -Maximum length? - Are connector characters allowed? - Are names case sensitive?

### Programming Languages Third Edition. Chapter 7 Basic Semantics

Programming Languages Third Edition Chapter 7 Basic Semantics Objectives Understand attributes, binding, and semantic functions Understand declarations, blocks, and scope Learn how to construct a symbol

### CS558 Programming Languages

CS558 Programming Languages Fall 2016 Lecture 7a Andrew Tolmach Portland State University 1994-2016 Values and Types We divide the universe of values according to types A type is a set of values and a

### TYPES, VALUES AND DECLARATIONS

COSC 2P90 TYPES, VALUES AND DECLARATIONS (c) S. Thompson, M. Winters 1 Names, References, Values & Types data items have a value and a type type determines set of operations variables Have an identifier

### 9/7/17. Outline. Name, Scope and Binding. Names. Introduction. Names (continued) Names (continued) In Text: Chapter 5

Outline Name, Scope and Binding In Text: Chapter 5 Names Variable Binding Type bindings, type conversion Storage bindings and lifetime Scope Lifetime vs. Scope Referencing Environments N. Meng, S. Arthur

### COS 140: Foundations of Computer Science

COS 140: Foundations of Computer Science Variables and Primitive Data Types Fall 2017 Introduction 3 What is a variable?......................................................... 3 Variable attributes..........................................................

### Chapter 5. Names, Bindings, and Scopes

Chapter 5 Names, Bindings, and Scopes Chapter 5 Topics Introduction Names Variables The Concept of Binding Scope Scope and Lifetime Referencing Environments Named Constants 1-2 Introduction Imperative

### For each of the following variables named x, specify whether they are static, stack-dynamic, or heapdynamic:

For each of the following variables named x, specify whether they are static, stack-dynamic, or heapdynamic: a) in C++: int* x = new(int); b) in Java: class book { protected string title; book(string x)

### CPSC 3740 Programming Languages University of Lethbridge. Data Types

Data Types A data type defines a collection of data values and a set of predefined operations on those values Some languages allow user to define additional types Useful for error detection through type

### G Programming Languages Spring 2010 Lecture 6. Robert Grimm, New York University

G22.2110-001 Programming Languages Spring 2010 Lecture 6 Robert Grimm, New York University 1 Review Last week Function Languages Lambda Calculus SCHEME review 2 Outline Promises, promises, promises Types,

### BLM2031 Structured Programming. Zeyneb KURT

BLM2031 Structured Programming Zeyneb KURT 1 Contact Contact info office : D-219 e-mail zeynebkurt@gmail.com, zeyneb@ce.yildiz.edu.tr When to contact e-mail first, take an appointment What to expect help

### Chapter 5 Names, Bindings, Type Checking, and Scopes

Chapter 5 Names, Bindings, Type Checking, and Scopes 長庚大學資訊工程學系 陳仁暉 助理教授 Tel: (03) 211-8800 Ext: 5990 E-mail: jhchen@mail.cgu.edu.tw URL: http://www.csie.cgu.edu.tw/jhchen All rights reserved. No part

### Fundamentals of Programming Languages

Fundamentals of Programming Languages 1. DEFINITIONS... 2 2. BUILT-IN TYPES AND PRIMITIVE TYPES... 3 TYPE COMPATIBILITY... 9 GENERIC TYPES... 14 MONOMORPHIC VERSUS POLYMORPHIC... 16 TYPE IMPLEMENTATION

### Final-Term Papers Solved MCQS with Reference

Solved MCQ(S) From FinalTerm Papers BY Arslan Jan 14, 2018 V-U For Updated Files Visit Our Site : Www.VirtualUstaad.blogspot.com Updated. Final-Term Papers Solved MCQS with Reference 1. The syntax of PHP

### Types. What is a type?

Types What is a type? Type checking Type conversion Aggregates: strings, arrays, structures Enumeration types Subtypes Types, CS314 Fall 01 BGRyder 1 What is a type? A set of values and the valid operations

### 22c:111 Programming Language Concepts. Fall Types I

22c:111 Programming Language Concepts Fall 2008 Types I Copyright 2007-08, The McGraw-Hill Company and Cesare Tinelli. These notes were originally developed by Allen Tucker, Robert Noonan and modified

### Full file at

Java Programming: From Problem Analysis to Program Design, 3 rd Edition 2-1 Chapter 2 Basic Elements of Java At a Glance Instructor s Manual Table of Contents Overview Objectives s Quick Quizzes Class

### Data Types, Variables and Arrays. OOC 4 th Sem, B Div Prof. Mouna M. Naravani

Data Types, Variables and Arrays OOC 4 th Sem, B Div 2016-17 Prof. Mouna M. Naravani Identifiers in Java Identifiers are the names of variables, methods, classes, packages and interfaces. Identifiers must

### COS 140: Foundations of Computer Science

COS 140: Foundations of Variables and Primitive Data Types Fall 2017 Copyright c 2002 2017 UMaine School of Computing and Information S 1 / 29 Homework Reading: Chapter 16 Homework: Exercises at end of

SE352b Software Engineering Design Tools W3: Programming Paradigms Feb. 3, 2005 SE352b, ECE,UWO, Hamada Ghenniwa SE352b: Roadmap CASE Tools: Introduction System Programming Tools Programming Paradigms

### CSE 452: Programming Languages. Where are we? Types: Intuitive Perspective. Data Types. High-level Programming Languages.

CSE 452: Programming Languages Data Types Where are we? Machine Language High-level Programming Languages Assembly Language Logic Object Oriented Imperative Functional You are here Concepts specification

### C++ Programming Fundamentals

C++ Programming Fundamentals 269 Elvis C. Foster Lecture 11: Templates One of the contemporary sophistries of C++ programming is defining and manipulating templates. This lecture focuses on this topic.

### Objectives. Chapter 2: Basic Elements of C++ Introduction. Objectives (cont d.) A C++ Program (cont d.) A C++ Program

Objectives Chapter 2: Basic Elements of C++ In this chapter, you will: Become familiar with functions, special symbols, and identifiers in C++ Explore simple data types Discover how a program evaluates

### Chapter 2: Basic Elements of C++

Chapter 2: Basic Elements of C++ Objectives In this chapter, you will: Become familiar with functions, special symbols, and identifiers in C++ Explore simple data types Discover how a program evaluates

### Data Types. Data Types. Introduction. Data Types. Data Types. Data Types. Introduction

Introduction Primitive Composite Structured Abstract Introduction Introduction Data Type is a Collection of Data Objects Possible r-values for a memory cell Set of operations on those objects Descriptor

### Chapter 2: Basic Elements of C++ Objectives. Objectives (cont d.) A C++ Program. Introduction

Chapter 2: Basic Elements of C++ C++ Programming: From Problem Analysis to Program Design, Fifth Edition 1 Objectives In this chapter, you will: Become familiar with functions, special symbols, and identifiers

### Chapter 6. Data Types ISBN

Chapter 6 Data Types ISBN 0-321 49362-1 Chapter 6 Topics Introduction Primitive Data Types Character String Types User-Defined Ordinal Types Array Types Associative Arrays Record Types Union Types Pointer

### Organization of Programming Languages CS3200 / 5200N. Lecture 06

Organization of Programming Languages CS3200 / 5200N Razvan C. Bunescu School of Electrical Engineering and Computer Science bunescu@ohio.edu Data Types A data type defines a collection of data objects

### Chapter 2 Working with Data Types and Operators

JavaScript, Fourth Edition 2-1 Chapter 2 Working with Data Types and Operators At a Glance Instructor s Manual Table of Contents Overview Objectives Teaching Tips Quick Quizzes Class Discussion Topics

### Chapter-8 DATA TYPES. Introduction. Variable:

Chapter-8 DATA TYPES Introduction To understand any programming languages we need to first understand the elementary concepts which form the building block of that program. The basic building blocks include

### C Language Part 1 Digital Computer Concept and Practice Copyright 2012 by Jaejin Lee

C Language Part 1 (Minor modifications by the instructor) References C for Python Programmers, by Carl Burch, 2011. http://www.toves.org/books/cpy/ The C Programming Language. 2nd ed., Kernighan, Brian,

### false, import, new 1 class Lecture2 { 2 3 "Data types, Variables, and Operators" 4

1 class Lecture2 { 2 3 "Data types, Variables, and Operators" 4 5 } 6 7 // Keywords: 8 byte, short, int, long, char, float, double, boolean, true, false, import, new Zheng-Liang Lu Java Programming 44

### HANDLING NONLOCAL REFERENCES

SYMBOL TABLE A symbol table is a data structure kept by a translator that allows it to keep track of each declared name and its binding. Assume for now that each name is unique within its local scope.

### Francesco Nidito. Programmazione Avanzata AA 2007/08

Francesco Nidito in the Programmazione Avanzata AA 2007/08 Outline 1 2 3 in the in the 4 Reference: Micheal L. Scott, Programming Languages Pragmatics, Chapter 7 What is a type? in the What is a type?

### Type Bindings. Static Type Binding

Type Bindings Two key issues in binding (or associating) a type to an identifier: How is type binding specified? When does the type binding take place? N. Meng, S. Arthur 1 Static Type Binding An explicit

### G Programming Languages - Fall 2012

G22.2110-003 Programming Languages - Fall 2012 Lecture 2 Thomas Wies New York University Review Last week Programming Languages Overview Syntax and Semantics Grammars and Regular Expressions High-level

### Tokens, Expressions and Control Structures

3 Tokens, Expressions and Control Structures Tokens Keywords Identifiers Data types User-defined types Derived types Symbolic constants Declaration of variables Initialization Reference variables Type

### 12 CREATING NEW TYPES

Lecture 12 CREATING NEW TYPES of DATA Typedef declaration Enumeration Structure Bit fields Uninon Creating New Types Is difficult to solve complex problems by using programs written with only fundamental

### Chapter 6. Structured Data Types. Topics. Structured Data Types. Vectors and Arrays. Vectors. Vectors: subscripts

Topics Chapter 6 Structured Data Types Vectors Arrays Slices Associative Arrays Records Unions Lists Sets 2 Structured Data Types Virtually all languages have included some mechanisms for creating complex

### CPS122 Lecture: From Python to Java last revised January 4, Objectives:

Objectives: CPS122 Lecture: From Python to Java last revised January 4, 2017 1. To introduce the notion of a compiled language 2. To introduce the notions of data type and a statically typed language 3.

### Zheng-Liang Lu Java Programming 45 / 79

1 class Lecture2 { 2 3 "Elementray Programming" 4 5 } 6 7 / References 8 [1] Ch. 2 in YDL 9 [2] Ch. 2 and 3 in Sharan 10 [3] Ch. 2 in HS 11 / Zheng-Liang Lu Java Programming 45 / 79 Example Given a radius

### Topic IV. Parameters. Chapter 5 of Programming languages: Concepts & constructs by R. Sethi (2ND EDITION). Addison-Wesley, 1996.

References: Topic IV Block-structured procedural languages Algol and Pascal Chapters 5 and 7, of Concepts in programming languages by J. C. Mitchell. CUP, 2003. Chapter 5 of Programming languages: Concepts

### CSCI312 Principles of Programming Languages!

CSCI312 Principles of Programming Languages! Chapter 5 Types Xu Liu! ! 5.1!Type Errors! 5.2!Static and Dynamic Typing! 5.3!Basic Types! 5.4!NonBasic Types! 5.5!Recursive Data Types! 5.6!Functions as Types!

### 3. Java - Language Constructs I

Educational Objectives 3. Java - Language Constructs I Names and Identifiers, Variables, Assignments, Constants, Datatypes, Operations, Evaluation of Expressions, Type Conversions You know the basic blocks

### Extending SystemVerilog Data Types to Nets

Extending SystemVerilog Data Types to Nets SystemVerilog extended Verilog by adding powerful new data types and operators that can be used to declare and manipulate parameters and variables. Extensions

### CS112 Lecture: Variables, Expressions, Computation, Constants, Numeric Input-Output

CS112 Lecture: Variables, Expressions, Computation, Constants, Numeric Input-Output Last revised January 12, 2006 Objectives: 1. To introduce arithmetic operators and expressions 2. To introduce variables

### Topic IV. Block-structured procedural languages Algol and Pascal. References:

References: Topic IV Block-structured procedural languages Algol and Pascal Chapters 5 and 7, of Concepts in programming languages by J. C. Mitchell. CUP, 2003. Chapters 10( 2) and 11( 1) of Programming

### A Fast Review of C Essentials Part I

A Fast Review of C Essentials Part I Structural Programming by Z. Cihan TAYSI Outline Program development C Essentials Functions Variables & constants Names Formatting Comments Preprocessor Data types

### Programming in C. What is C?... What is C?

C Programming in C UVic SEng 265 Developed by Brian Kernighan and Dennis Ritchie of Bell Labs Earlier, in 1969, Ritchie and Thompson developed the Unix operating system We will be focusing on a version

### Programming in C UVic SEng 265

Programming in C UVic SEng 265 Daniel M. German Department of Computer Science University of Victoria 1 SEng 265 dmgerman@uvic.ca C Developed by Brian Kernighan and Dennis Ritchie of Bell Labs Earlier,

### Programming in C. What is C?... What is C?

Programming in C UVic SEng 265 C Developed by Brian Kernighan and Dennis Ritchie of Bell Labs Earlier, in 1969, Ritchie and Thompson developed the Unix operating system We will be focusing on a version

### CS558 Programming Languages

CS558 Programming Languages Winter 2017 Lecture 7b Andrew Tolmach Portland State University 1994-2017 Values and Types We divide the universe of values according to types A type is a set of values and

### PROGRAMMING IN C++ COURSE CONTENT

PROGRAMMING IN C++ 1 COURSE CONTENT UNIT I PRINCIPLES OF OBJECT ORIENTED PROGRAMMING 2 1.1 Procedure oriented Programming 1.2 Object oriented programming paradigm 1.3 Basic concepts of Object Oriented

### CS112 Lecture: Primitive Types, Operators, Strings

CS112 Lecture: Primitive Types, Operators, Strings Last revised 1/24/06 Objectives: 1. To explain the fundamental distinction between primitive types and reference types, and to introduce the Java primitive

### Haskell 98 in short! CPSC 449 Principles of Programming Languages

Haskell 98 in short! n Syntax and type inferencing similar to ML! n Strongly typed! n Allows for pattern matching in definitions! n Uses lazy evaluation" F definition of infinite lists possible! n Has

### Lecture Overview. [Scott, chapter 7] [Sebesta, chapter 6]

1 Lecture Overview Types 1. Type systems 2. How to think about types 3. The classification of types 4. Type equivalence structural equivalence name equivalence 5. Type compatibility 6. Type inference [Scott,

### Chapter 2 Basic Elements of C++

C++ Programming: From Problem Analysis to Program Design, Fifth Edition 2-1 Chapter 2 Basic Elements of C++ At a Glance Instructor s Manual Table of Contents Overview Objectives s Quick Quizzes Class Discussion

### Object-Oriented Principles and Practice / C++

Object-Oriented Principles and Practice / C++ Alice E. Fischer April 20, 2015 OOPP / C++ Lecture 3... 1/23 New Things in C++ Object vs. Pointer to Object Optional Parameters Enumerations Using an enum

### Data Types. Outline. In Text: Chapter 6. What is a type? Primitives Strings Ordinals Arrays Records Sets Pointers 5-1. Chapter 6: Data Types 2

Data Types In Text: Chapter 6 1 Outline What is a type? Primitives Strings Ordinals Arrays Records Sets Pointers Chapter 6: Data Types 2 5-1 Data Types Two components: Set of objects in the type (domain

### Organization of Programming Languages CS320/520N. Lecture 06. Razvan C. Bunescu School of Electrical Engineering and Computer Science

Organization of Programming Languages CS320/520N Razvan C. Bunescu School of Electrical Engineering and Computer Science bunescu@ohio.edu Data Types A data type defines a collection of data objects and

### Introduction To C#.NET

Introduction To C#.NET Microsoft.Net was formerly known as Next Generation Windows Services(NGWS).It is a completely new platform for developing the next generation of windows/web applications. However

### Lecture 3. The syntax for accessing a struct member is

Lecture 3 Structures: Structures are typically used to group several data items together to form a single entity. It is a collection of variables used to group variables into a single record. Thus a structure

### false, import, new 1 class Lecture2 { 2 3 "Data types, Variables, and Operators" 4

1 class Lecture2 { 2 3 "Data types, Variables, and Operators" 4 5 } 6 7 // Keywords: 8 byte, short, int, long, char, float, double, boolean, true, false, import, new Zheng-Liang Lu Java Programming 44

### Software II: Principles of Programming Languages

Software II: Principles of Programming Languages Lecture 6 Data Types Some Basic Definitions A data type defines a collection of data objects and a set of predefined operations on those objects A descriptor

### A data type defines a collection of data objects and a set of predefined operations on those objects

Data Types Introduction A data type defines a collection of data objects and a set of predefined operations on those objects Language selection criterion who well does supported data types match problem

### CS 231 Data Structures and Algorithms, Fall 2016

CS 231 Data Structures and Algorithms, Fall 2016 Dr. Bruce A. Maxwell Department of Computer Science Colby College Course Description Focuses on the common structures used to store data and the standard

### CS112 Lecture: Working with Numbers

CS112 Lecture: Working with Numbers Last revised January 30, 2008 Objectives: 1. To introduce arithmetic operators and expressions 2. To expand on accessor methods 3. To expand on variables, declarations

### The New C Standard (Excerpted material)

The New C Standard (Excerpted material) An Economic and Cultural Derek M. Jones derek@knosof.co.uk Copyright 2002-2008 Derek M. Jones. All rights reserved. 1378 type specifier type-specifier: void char

### Chapter 6. Data Types. *modified by Stephanie Schwartz ISBN

Chapter 6 Data Types *modified by Stephanie Schwartz ISBN 0-321 49362-1 Chapter 6 Topics Introduction Primitive Data Types Character String Types Enumeration Types Array Types Associative Arrays Record

### VARIABLES AND TYPES CITS1001

VARIABLES AND TYPES CITS1001 Scope of this lecture Types in Java the eight primitive types the unlimited number of object types Values and References The Golden Rule Primitive types Every piece of data

### Basics of Java Programming

Basics of Java Programming Lecture 2 COP 3252 Summer 2017 May 16, 2017 Components of a Java Program statements - A statement is some action or sequence of actions, given as a command in code. A statement

### COE318 Lecture Notes Week 3 (Week of Sept 17, 2012)

COE318 Lecture Notes: Week 3 1 of 8 COE318 Lecture Notes Week 3 (Week of Sept 17, 2012) Announcements Quiz (5% of total mark) on Wednesday, September 26, 2012. Covers weeks 1 3. This includes both the

### 1. Describe History of C++? 2. What is Dev. C++? 3. Why Use Dev. C++ instead of C++ DOS IDE?

1. Describe History of C++? The C++ programming language has a history going back to 1979, when Bjarne Stroustrup was doing work for his Ph.D. thesis. One of the languages Stroustrup had the opportunity

### Input And Output of C++

Input And Output of C++ Input And Output of C++ Seperating Lines of Output New lines in output Recall: "\n" "newline" A second method: object endl Examples: cout

### Design Principles for a Beginning Programming Language

Design Principles for a Beginning Programming Language John T Minor and Laxmi P Gewali School of Computer Science University of Nevada, Las Vegas Abstract: We consider the issue of designing an appropriate

### Informatica 3 Syntax and Semantics

Informatica 3 Syntax and Semantics Marcello Restelli 9/15/07 Laurea in Ingegneria Informatica Politecnico di Milano Introduction Introduction to the concepts of syntax and semantics Binding Variables Routines

### BASIC ELEMENTS OF A COMPUTER PROGRAM

BASIC ELEMENTS OF A COMPUTER PROGRAM CSC128 FUNDAMENTALS OF COMPUTER PROBLEM SOLVING LOGO Contents 1 Identifier 2 3 Rules for naming and declaring data variables Basic data types 4 Arithmetic operators

### Duhok Polytechnic University Amedi Technical Institute/ IT Dept. Halkawt Rajab Hussain

Duhok Polytechnic University Amedi Technical Institute/ IT Dept. By Halkawt Rajab Hussain 2016-04-02 Overview. C# program structure. Variables and Constant. Conditional statement (if, if/else, nested if

### Note 3. Types. Yunheung Paek. Associate Professor Software Optimizations and Restructuring Lab. Seoul National University

Note 3 Types Yunheung Paek Associate Professor Software Optimizations and Restructuring Lab. Seoul National University Topics Definition of a type Kinds of types Issues on types Type checking Type conversion

### Basic Elements of C. Staff Incharge: S.Sasirekha

Basic Elements of C Staff Incharge: S.Sasirekha Basic Elements of C Character Set Identifiers & Keywords Constants Variables Data Types Declaration Expressions & Statements C Character Set Letters Uppercase