Thread: use of System.out.println(""); error....

The println calls need to be inside of a method or constructor.
Statements outside of methods are executed when the class is instantiated. They are for defining and initializing variables.

You can do this if you put your printing code inside an initialization block. This will get executed once for every instance, before the constructor runs. For example:

class A {
    int a = 1;
    {                                            // open initialization block
        System.out.println(" a is  "+a);     
        System.out.println();                  
    }                                            // close initialization block
 
    void cal() {
        int b = 2;
        System.out.println(" b is " + b);   //working fine
    }
}

This is not recommended practice unless you have a good reason for doing it, and in my experience, is rarely, if ever necessary.