Find the output for the following program

Find the output for the following program:
==================================
package blog;

public class IfElseDemo {

public static void main(String[] args) {

int a=10,b=20;

if (a=b) 
{
System.out.println("a is bigger");
System.out.println("value of a is : " +a);
System.out.println("value of b is : " +b);
}
else
{
System.out.println("b is smaller");
}

}

}

1.   Compile Time Error

2.   Null PointerException

3.   NoSuchElementException

4.   None of the above

ANSWER : Compile time error.