JAVA LANGUAGE FUNDAMENTALS MCQs

Which four options describe the correct default values for array elements of the types indicated

1. int -> 0
2. String -> "null"
3. Dog -> null
4. char -> '\u0000'
5. float -> 0.0f
6. boolean -> true

Which one of these lists contains only Java programming language keywords?

Which will legally declare, construct, and initialize an array?

Which is a reserved word in the Java programming language?

Which is a valid keyword in java?

Which three are valid declarations of a float?
1. float f1 = -343;
2. float f2 = 3.14;
3. float f3 = 0x12345;
4. float f4 = 42e7;
5. float f5 = 2001.0D;
6. float f6 = 2.81F;

Which is a valid declarations of a String?

What is the numerical range of a char?

Which three are legal array declarations?
1. int [] myScores [];
2. char [] myChars;
3. int [6] myScores;
4. Dog myDogs [];
5. Dog myDogs [7];

Which three piece of codes are equivalent to line 3?
1. final int k = 4;
2. public int k = 4;
3. static int k = 4;
4. abstract int k = 4;
5. volatile int k = 4;
6. protected int k = 4;

public interface Foo 
{ 
    int k = 4; /* Line 3 */
}

Which one of the following will declare an array and initialize it with five numbers?

Which three are valid declarations of a char?
1. char c1 = 064770;
2. char c2 = 'face';
3. char c3 = 0xbeef;
4. char c4 = \u0022;
5. char c5 = '\iface';
6. char c6 = '\uface';

Which is the valid declarations within an interface definition?

What will be the output of the program?

Note: The command-line invocation is
> java CommandArgsThree 1 2 3

public class CommandArgsThree 
{
    public static void main(String [] args) 
    {
        String [][] argCopy = new String[2][2];
        int x;
        argCopy[0] = args;
        x = argCopy[0].length;
        for (int y = 0; y < x; y++) 
        {
            System.out.print(" " + argCopy[0][y]);
        }
    }
}

What will be the output of the progra
Note: The command-line invocation is
> java CommandArgs 1 2 3 4

public class CommandArgs 
{
    public static void main(String [] args) 
    {
        String s1 = args[1];
        String s2 = args[2];
        String s3 = args[3];
        String s4 = args[4];
        System.out.print(" args[2] = " + s2);
    }
}

What will be the output of the program, if this code is executed with the command line:

> java F0091 world

public class F0091 
{    
    public void main( String[] args ) 
    {  
        System.out.println( "Hello" + args[0] ); 
    } 
}

What will be the output of the program?

public class TestDogs 
{
    public static void main(String [] args) 
    {
        Dog [][] theDogs = new Dog[3][];
        System.out.println(theDogs[2][0].toString());
    }
}
class Dog { }

What will be the output of the program ?

public class Test 
{
    public static void main(String [] args) 
    {
        signed int x = 10;
        for (int y=0; y<5; y++, x--)
            System.out.print(x + ", ");
    }
}

What will be the output of the program

Note: The command-line invocation is
> java CommandArgsTwo 1 2 3

public class CommandArgsTwo 
{
    public static void main(String [] argh) 
    {
        int x;
        x = argh.length;
        for (int y = 1; y <= x; y++) 
        {
            System.out.print(" " + argh[y]);
        }
    }
}

In the given program, how many lines of output will be produced?

public class Test 
{
    public static void main(String [] args) 
    {
    int [] [] [] x = new int [3] [] [];
    int i, j;
    x[0] = new int[4][];
    x[1] = new int[2][];
    x[2] = new int[5][];
    for (i = 0; i < x.length; i++)
    {
        for (j = 0; j < x[i].length; j++) 
        {
            x[i][j] = new int [i + j + 1];
            System.out.println("size = " + x[i][j].length);
        }
    }
    }
}