...
If you do not want to change a and b after they are initialized, the simplest approach is to declare a and b final:
| Code Block |
|---|
 void set_ab(int a, int b){ //But now compiler complains about set_ab method!
  this.a = a;
  this.b = b;
 }
 private final int a;
 private final int b;
|
But now you can not have setter method methods of a and b.
Compliant Solution
...