Introduction to C/C++ Lecture 1 - Introduction to Programming

Transcription

1 Introduction to C/C++ Lecture 1 - Introduction to Programming Rohit Sehgal Nishit Majithia Association of Computing Activities, Indian Institute of Technology,Kanpur rsehgal@cse.iitk.ac.in nishitm@cse.iitk.ac.in May 23, 2016 Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

2 Overview Content Coverage of the Course: Elements of C/C++ programming languages Data types Sequential and conditional execution,loops Arrays,pointers Strings and their Manipulation Functions User Defined Data Types in C Migrating to C++,User defined Data Types Classes Generic Programming Using Templates and STL Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

3 Course Scheme Course Website Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

4 Course Scheme Course Website Evaluation One Quiz After first week Two programming Assignment Final Exam at the end of the course Practice problems(ungraded) will uploaded after every lecture on course webpage Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

5 Course Scheme Course Website Evaluation One Quiz After first week Two programming Assignment Final Exam at the end of the course Practice problems(ungraded) will uploaded after every lecture on course webpage Course Timings to week days Extra Classes will be announced. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

6 Code of conduct strictly obey the rules of the CSE Department. Any destruction (specially writing stuff on benches) will result in the cancellation of registration. Since every registered student is given an ID (badge) mentioning the code of the courses he/she has registered. You are supposed to wear it in the class. You can use Ground floor labs to access PC(possibly try to bring laptops), you may ask Ankita(CSE Office) to provide you with userid/passwd to access PCs and wifi. Please Don t hog the PCs for long. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

7 Suggestions? Questions? Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

8 Computer Languages? Computer being an electronic device understand ON/OFF Signals. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

9 Computer Languages? Computer being an electronic device understand ON/OFF Signals. Series of ON/OFF Instructions analogous to 1/0(binary Instructions). Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

10 Computer Languages? Computer being an electronic device understand ON/OFF Signals. Series of ON/OFF Instructions analogous to 1/0(binary Instructions). Binary codes provides way to interact to Computers,Machine Language Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

11 Computer Languages? Computer being an electronic device understand ON/OFF Signals. Series of ON/OFF Instructions analogous to 1/0(binary Instructions). Binary codes provides way to interact to Computers,Machine Language Computer can do intended task,if provided with meaningful string of 0,1(s) as these ON/OFF signals controls different components of computers viz ALU,CU etc Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

12 Computer Languages? Computer being an electronic device understand ON/OFF Signals. Series of ON/OFF Instructions analogous to 1/0(binary Instructions). Binary codes provides way to interact to Computers,Machine Language Computer can do intended task,if provided with meaningful string of 0,1(s) as these ON/OFF signals controls different components of computers viz ALU,CU etc Cumbersome to write a binary string even to add two nos. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

13 Computer Languages? Computer being an electronic device understand ON/OFF Signals. Series of ON/OFF Instructions analogous to 1/0(binary Instructions). Binary codes provides way to interact to Computers,Machine Language Computer can do intended task,if provided with meaningful string of 0,1(s) as these ON/OFF signals controls different components of computers viz ALU,CU etc Cumbersome to write a binary string even to add two nos. Solution Assembly language? Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

14 Languages Above Machine Language Assembly Language provides Mnemonics. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

15 Languages Above Machine Language Assembly Language provides Mnemonics. E.g ADD,LOAD,STORE, need not to remember binary codes(s) for these Operations. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

16 Languages Above Machine Language Assembly Language provides Mnemonics. E.g ADD,LOAD,STORE, need not to remember binary codes(s) for these Operations. Assembler,converts Assembly Language to Machine. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

17 Languages Above Machine Language Assembly Language provides Mnemonics. E.g ADD,LOAD,STORE, need not to remember binary codes(s) for these Operations. Assembler,converts Assembly Language to Machine. Programming in Assembly, Why not something similar to Natural Languages like English. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

18 Languages Above Machine Language Assembly Language provides Mnemonics. E.g ADD,LOAD,STORE, need not to remember binary codes(s) for these Operations. Assembler,converts Assembly Language to Machine. Programming in Assembly, Why not something similar to Natural Languages like English. High level Languages C,C++,Java,python Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

19 C/C++ Compiler Convert HLL to Assembly. Programming Computers is now easier. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

20 C/C++ Compiler Convert HLL to Assembly. Programming Computers is now easier. Example (Compilers for C/C++) $ gcc <filename.c> -o <outputfilename> $ g++ <filename.cpp> -o <outputfilename>.c,.cpp are the file extensions for C,C++ source file respectively. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

21 Compiling and Running Linux users gcc,g++ $ sudo apt-get install gcc g++ Windows users: Install Virtual Machine with Linux system. Ubuntu Linux System 0B78zyZuoC7SAbE00UEplWDEwQzQ/view User-name - intro2c Password - summerschool OR,Install Mingw, In class, we will be working with Linux System Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

22 Our First Program Example (C) #include<stdio.h> int main() { printf("hello World"); return 0; } Example (C++) #include<iostream> using namespace std; int main() { cout<<"hello World"; return 0; } Now on-wards we will follow C s syntax. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

23 # pre-processor Directives Replaced before compilation starts. $ gcc -E demo.c > preprocessed file.dat #include<>,#include, includes the content of file in source file. these file stores declarations of functions functions are part of program that does some computations details in functions lecture others #define,#ifdef,#ifndef etc. #define - text replacement blindly. e.g Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

24 The Main function Entry point of code execution as program may contain several functions. body of any function is enclosed with { } return 0??, exit status, we will see later. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

25 printf writes to standard output(monitor). first argument is always a format specifier-how the output is printed to screen. Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

26 Comments Compiler do not read comments. // this is a single line comment. /* this comment spans multiple lines */ Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

27 1 #i n c l u d e <s t d i o. h> 2 #d e f i n e N 10 3 / Block 4 comment / 5 6 i n t main ( ) 7 { 8 i n t i ; 9 0 // L i n e comment. 1 printf ( H e l l o World %d, N ) ; // p r i n t s to s t d output 2 r e t u r n 0 ; 3 } Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15

28 The End Rohit Sehgal Nishit Majithia (IITK) ACA May 23, / 15