覆盖等于方法问题

Question

I'm trying to make a rational numbers class and override the equals and hash code methods. But my equals is coming back true in cases were its clearly not true ie the numerator and denominator are different. Any idea what could be causing this?

public boolean equals(Object rhs) {
    if (this == rhs){
        return true;
    }
    if (rhs == null){
        return false;
    }
    if (!(rhs instanceof Rational)){
        return false;
    }
    Rational other = (Rational) rhs;
    if (denom == other.denom){
        if (num == other.num);{
            return true;
        }
    }
    return false;
}

Answer 1

Here is the problem (if not a typo):

if (num == other.num);{

The semicolon means that the if statement is an empty statement, so its evaluation doesn't really get involved in the equals validation process. Just remove the semi colon:

if (num == other.num){

Answer 2

Remove the semicolon on this line, which is acting as the body for the if statement.

if (num == other.num);{

With the semicolon, if the denominators are equal, then true will be returned; the check of the numerators is effectively ignored.

Answer 3

Remove the ; after if (num == other.num); { if (num == other.num); { , changint it to if (num == other.num) {

Leaving it there, it basically does nothing after the if , then enters the block :

{
    return true;
}

So it will always return true at that point.