Why does this() and super() have to be the first statement in a constructor?

[Vimil Saju]

If you have subclass then java requires that this() or super has to be first statement in the constructor of the subclass. 
Here is an example
 
publicclassMyClass{
        publicMyClass(intx){}
}

publicclassMySubClassextendsMyClass{
        publicMySubClass(inta,intb){
                intc =a +b;
                super(c); // COMPILE ERROR
        }
}The above compilation error can be resolved by rewriting the code in the constructor as follows

publicclassMySubClassextendsMyClass{
        publicMySubClass(inta,intb){
                super(a + b); 
        }
}Can't the Java compiler detect that in the previous code there was no access to the instance fields or methods and therefore allow the code to compile without any error.