K E Y I CYCLIC, EXAMINATION SECTION A

Transcription

1 Question 1: (a) 0 to 65,535 SECTION A (b) Precision (i) float 6 digits (ii) double 15 digits (c) Attributes to declare a class Data members and Member functions (d) The two types of Java programs are 1. Internet Applets and 2. Standalone applications (e) Keyword (i) (ii) break class Question 2: (a) <access_specifier> <data_type> <identifier>; (b) The conventions to construct a class name (i) A class name must begin with an upper case alphabet (ii) Every subsequent word s first letter must be capital. (c) The two forms of a real number (i) Fractional (ii) Exponential (d) There are nine seperators [ ] ( )., ; (e) x = 5; x = x++ * * --x; 5 * * Page 1 of 6

2 Question 3: (a) The implicit conversion wherein data types are promoted is known as coercion. (b) ClassName objectname = new ClassName(parameters); (c)? and : are conditional operators, there are the shorthand operators for if else. The conditional operators are also known as ternary operators. Syntax: (expression_1)?( expression_2):( expression_3); (d) An abstract machine which hides the underlying operating system from Java applications and executes the Java Byte Code. (e) Differences between while and do while. S.no while do while 1. It is an entry level check It is an exit level check 2. Block of statements are executed depending upon the test condition. The block of statements are executed at least once irrespective of the test condition. Question 4: (a) Wrapper Classes: These are the pre defined classes in the package java.lang.*. These classes are used to convert the String object to primitive data types. (b) Contradictory or Unexpected situation or unexpected error, during program execution, is known as Exception. (c) (d) Differences between primitive and derived data types. S.No. Primitive data types Derived data types 1. These are the built in types. These are created by the programmer using the primitive data types. 2. They have standard default The default value is null. values. 3. They reserve standard The memory depends upon the memory. 4. There are 8 primitive data types. constituent data members. There can be n number of data types. (e) (i) (ii) Java.lang.*; Java.util.*; (f) Default value of (i) char null (ii) boolean false Page 2 of 6

3 Question 5. SECTION B // Area of a circle class Area private double a,r; private String s; InputStreamReader isr = new InputStreamReader(System.in); BufferedReader br = new BufferedReader(isr); // accept the radius of the circle System.out.print("Enter the radius of the circle : "); s=br.readline(); r=double.parsedouble(s); // find the area of the circle a=math.pi*r*r; // display the area of the circle System.out.print("The area of the circle = "+a); Enter the radius of the circle : 1.0 The area of the circle = Variable Description: 1. r double To store the radius of the circle 2. a double To store the area of the circle 3. s String To store the accepted string from the terminal 4. isr InputStreamReader Instance of InputStreamReader 5. br BufferedReader Instance of BufferedReader Page 3 of 6

4 Question 6: // vowel or a consonant class Grammar private char ch; // read the alphabet System.out.print("Enter an alphabet : "); ch=(char)system.in.read(); // test whether the alphabet is a vowel if(ch=='a' ch=='e' ch=='i' ch=='o' ch=='u') System.out.print(ch+" is a vowel"); else // test the alphabet for consonant if(ch>=97 && ch<=122) System.out.print(ch+" is a consonant"); else // test for alphabet or not System.out.print(ch+" is not an alphabet"); Enter an alphabet : e e is a vowel Enter an alphabet : p p is a consonant Enter an alphabet : * * is not an alphabet Variable Description: 1. ch char To store the accepted alphabet Page 4 of 6

5 Question 7: // find the factorial of a number class Factorial private int n,i,f=1; private String s; InputStreamReader isr = new InputStreamReader(System.in); BufferedReader br = new BufferedReader(isr); // read the number System.out.print("Enter a number : "); s=br.readline(); n=integer.parseint(s); // find the factorial for(i=1;i<=n;i++) f=f*i; // display the factorial System.out.print("The factorial of "+n+" = "+f); Enter a number : 5 The factorial of 5 = 120 Variable Desctiption: 1. n int To store the accepted number 2. i int Used in iteration 3. f int To store the factorial 4. s String To store the accepted string 5. isr InputStreamReader Instance of InputStreamReader 6. br BufferedReader Instance of BufferedReader Page 5 of 6

6 Question 8. // reverse of a string class Reverse private String s; InputStreamReader isr = new InputStreamReader(System.in); BufferedReader br = new BufferedReader(isr); // accept the text System.out.print("Enter a string : "); s=br.readline(); // display the string before reverse System.out.println("The string before reverse \""+s+"\""); // convert the String object to StringBuffer object StringBuffer sb = new StringBuffer(s); // find the reverse sb.reverse(); // convert StringBuffer to String s=sb.tostring(); // display the string after reverse System.out.println("The string after reverse \""+s+"\""); Enter a string : James Gosling The string before reverse "James Gosling" The string after reverse "gnilsog semaj" Variable Description: 1. s String To store the accepted string 2. sb StringBuffer Instance of StringBuffere 2. isr InputStreamReader Instance of InputStreamReader 6. br BufferedReader Instance of BufferedReader Page 6 of 6