Java Programming Practice Test 3

1. What will be the output of the following Java program?

 
    class output 
    {
        public static void main(String args[])
        { 
           String s1 = "Hello";
           String s2 = s1.replace('l','w');
           System.out.println(s2);
        }
    }

hello

hewwo

helwo

hewlo

2. What will be the output of the following Java program?

 
    class output 
    {
        public static void main(String args[])
        {
           String s1 = "Hello World";
           String s2 = s1.substring(0 , 4);
           System.out.println(s2);
        }
   }

World

Hell

Hello

Worl

3. Which of these method of class String is used to extract more than one character at a time a String object?

Getchars()

getchars()

getChars()

GetChars()

4. What will be the output of the following Java snippet, if attempted to compile and execute?

class abc
{
    public static void main(String args[])
    {
        if(args.length>0)
        System.out.println(args.length);
    }
}

The snippet compiles and runs but does not print anything

The snippet compiles, runs and prints 1

The snippet does not compile

The snippet compiles, runs and prints 0

5. Which annotation is used to represent command line input and assigned to correct data type?

@Variable

@Input

@Command Line

@Parameter

6. What will be the output of the following Java code?

 
    class output 
    {
        public static void main(String args[])
        { 
           String s1 = "Hello";
           String s2 = new String(s1);
           String s3 = "HELLO";
           System.out.println(s1.equals(s2) + " " + s2.equals(s3));
        }
    }

false true

true false

true true

false false

7. Which of these is an incorrect statement?

String object can point to some other reference of String variable

StringBuffer class is used to store string in a buffer for later use

String objects are immutable, they cannot be changed

None of the mentioned

8. What is the use of @syntax?

Allows one to put all your options into a file and pass this file as a parameter

Allows multiple parameters to be passed

Allows one to pass one file containing only one parameter

Allows one to pass only one parameter

9. What will be the output of the following Java program, Command line exceution is done as - "java Output This is a command Line"?

    class Output 
    {
        public static void main(String args[]) 
        {
            System.out.print(args[3]);
        }
    }

This

java

command

10. What will be the output of the following Java program?

    class box 
    {
        int width;
        int height;
        int length;
        int volume;
        void volume(int height, int length, int width) 
        {
             volume = width * height * length;
        } 
    }    
    class Prameterized_method{
        public static void main(String args[]) 
        {
            box obj = new box();
            obj.height = 1;
            obj.length = 5;
            obj.width = 5;
            obj.volume(3, 2, 1);
            System.out.println(obj.volume);        
        } 
    }