Output of Java Programs | Set 48 (Static keyword)

Prerequisite : Static keyword in Java

Question 1. what is the output of this question?

class Test1 {
public
    static void main(String[] args)
    {
        int x = 20;
        System.out.println(x);
    }
    static
    {
        int x = 10;
        System.out.print(x + " ");
    }
}

Option
A) 10 20
B) 20 10
C) 10 10
D) 20 20

Output: A

Explanation : Static block is executed before main method. If we declare a Static block in java class it is executed when class loads.

Question 2. what is the output of this question?

class Test1 {
    int x = 10;
public
    static void main(String[] args)
    {
        System.out.println(x);
    }
    static
    {
        System.out.print(x + " ");
    }
}

Option
A) 10 10
B) Error
C) Exception
D) none

Output: B

Explanation : If we are trying to print the instance variable inside the static block or static method without creating class instance then it will give the error : non-static variable x cannot be referenced from a static context.

Question 3. what is the output of this question?

class Test1 {
    int x = 10;
public
    static void main(String[] args)
    {
        Test1 t1 = new Test1();
        System.out.println(t1.x);
    }
    static
    {
        int x = 20;
        System.out.print(x + " ");
    }
}

Option
A) 10 20
B) 20 10
C) 10 10
D) Error

Output: B

Explanation : We can print the instance variable inside the static method after creating the class reference.

Question 4. what is the output of this question?

class Test1 {
    int x = 10;
public
    static void main(String[] args)
    {
        System.out.println(Test1.x);
    }
    static
    {
        int x = 20;
        System.out.print(x + " ");
    }
}

Option
A)10 10
B) 20 20
C) 20 10
D) Error

Output: D

Explanation : We can not access the instance variable with class name. otherwise it will give the error : non-static variable x cannot be referenced from a static context

Question 5. what is the output of this question?

class Test1 {
    static int x = 10;
public
    static void main(String[] args)
    {
        Test1 t1 = new Test1();
        Test1 t2 = new Test1();

        t1.x = 20;
        System.out.print(t1.x + " ");
        System.out.println(t2.x);
    }
}

Option
A) 10 10
B) 20 20
C) 10 20
D) 20 10

Output: B

Explanation : static variable is class level variable. if we do update in any reference then automatically all pointing reference value are changed.