Java Intermediate (Level 1)

Q 1.

How to format date from one form to another?

SimpleDateFormat DateFormat SimpleFormat DateConverter

Q 2.

How to convert a String to a Date object?

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-mm-dd"); sdf.parse(new Date()); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-mm-dd"); sdf.format(new Date()); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-mm-dd"); new Date().parse(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-mm-dd"); new Date().format();

Q 3.

Which of these is long data type literal?

0x99fffL ABCDEFG 0x99fffa 99671246

Q 4.

What will be the output of the following Java program?

 class variable_scope
    { 
        public static void main(String args[]) 
        { 
            int x;
            x = 5;
            {
                int y = 6;
                System.out.print(x + " " + y); 
            } 
            System.out.println(x + " " + y);
        } 
    }

5 6 5 6 5 6 5 Runtime error Compilation error

Q 5.

Which of these operators is used to allocate memory to array variable in Java?

malloc alloc new new malloc

Q 6.

Which of these is necessary to specify at time of array initialization?

Row Column Both Row and Column None of the mentioned

Q 7.

What will be the output of the following Java code?

class array_output {
    public static void main(String args[]) {
        int array_variable[] = new int[10];
        for (int i = 0; i < 10; ++i) {
            array_variable[i] = i;
            System.out.print(array_variable[i] + " ");
            i++;
        }
    }
}

0 2 4 6 8 1 3 5 7 9 0 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 10

Q 8.

What is the type of variable ‘b’ and ‘d’ in the following Java snippet?

int a[], b; 
int []c, d;

‘b’ and ‘d’ are int ‘b’ and ‘d’ are arrays of type int ‘b’ is int variable; ‘d’ is int array ‘d’ is int variable; ‘b’ is int array

Q 9.

How to copy contents of array?

System.arrayCopy() Array.copy() Arrays.copy() Collection.copy()

Q 10.

Where is an array stored in memory?

heap space stack space heap space and stack space first generation memory

Q 11.

Which of these statements are incorrect?

The left shift operator, <<, shifts all of the bits in a value to the left specified number of times The right shift operator, >>, shifts all of the bits in a value to the right specified number of times The left shift operator can be used as an alternative to multiplying by 2 The right shift operator automatically fills the higher order bits with 0

Q 12.

What will be the output of the following Java program?

class leftshift_operator
    { 
        public static void main(String args[])
        {
            byte x = 64;
            int i;
            byte y;
            i = x << 2;
            y = (byte)(x << 2);
            System.out.print(i + " " + y);
        } 
    }

0 64 64 0 0 256 256 0

Q 13.

What will be the output of the following Java code?

class ternary_operator {
    public static void main(String args[]) {
        int x = 3;
        int y = ~x;
        int z;
        z = x > y ? x : y;
        System.out.print(z);
    }
}

0 1 3 -4

Q 14.

Which of the below is invalid identifier with the main method?

public static private final

Q 15.

How can we identify whether a compilation unit is class or interface from a .class file?

Java source file header Extension of compilation unit We cannot differentiate between class and interface The class or interface name should be postfixed with unit type

Instruction