Question

Predict the output of following Java program

class T {
int t= 20;
T() {
t = 40
}
}
class Main {
public static void main(String args[]) {
   T t1 = new T();
   System.out.println(t1.t);
}
}

a.20

b.Garbage value

c.40

d.Compiler Error

Answer 1

Answer:

Note: Please check your code once, if there is semicolon at the end of the line 4 or not that is t=40.

If there is no semi-colon:

The below is the answer if there is no semi colon.

d.Compile error.

The below is the error:

Main.java:12: error: ';' expected
t = 40
      ^
1 error

because semicolon is missing at the end of the line that is t=40. it must be t=40;

If there is semi-colon:

The below is the answer if there is semi-colon in the line t=40.

c.40

Because T is class which consists a constructor and a variable t. initially t value 20 but in the main function T class object t1 is created. At the time of creation the constructor in T class is called and in constructor t becomes 40 so the t value is 40.So the output is 40.

Don't forget to check your code that consists semi-colon in line t=40 or not.