Answer to Question #20041 in Java | JSP | JSF for nohra

Question

9.Where should the following statement be located in the body of a subclass constructor?
super( );

Answer 1

Constructor call must be the first statement in aconstructor
if you try to set up some variables and then call aconstructor. You need to construct the object first, then modify it.

WRONG
publicclass Foo {
int i;
public Foo() {
i = 2;
}
public Foo(int x) { // fine
this();
this.i = x;
}
public Foo(int x, int y) {
int z = x*y;
this(z); // not okay
}
}

RIGHT
publicclass Foo {
int i;
public Foo() {
i = 2;
}
public Foo(int x) {
this();
this.i = x;
}
public Foo(int x, int y) {
this(x*y); // now okay
}
}