I am trying to change the compareTo after @override to a boolean function. This function will take a generic Object o and return whether or not it equals that Ingredient object. The only attribute in ingredient is name. So cast Object o to a Ingredient and then return whether the string names equal.

public class Ingredient implements Comparable<Ingredient> {

    private String name;
    
    public Ingredient(String name) {
        this.name = name;
    }
    
    public String getName() {
        return this.name;
    }

    /**
     * Compares two ingredients.
     * 
     * note: if we add other ingredient attributes,
     * we will need to change this method.
     */
    @Override
    public int compareTo(Ingredient other) {
        return this.name.compareTo(other.name);
    }
    

}

So, I change the last function to: Does this work? Or, am I on the right track...

public boolean equals(Object o){
            if(this == o) return true;
            Ingredient ingredient = (Ingredient)o;
            if(ingredient.name.equals(this.name)) {
                return true;
            } else return false;
    }

CodePudding user response：

You don't even have to use an interface.

According to the Java Docs, a Comparable is being used specify and order, e.g. sorting an Array.

To check for equality, you have to override the method equals (and not even implement some interface), which returns a boolean:

• true for equality
• false for inequality

Also, changing the return type of inherited methods is not allowed in java.

CodePudding user response：

You are overwriting the int compareTo() Method of the Object class. There is no bool compareTo() to overwrite. It just doesn't exists.

When overwriting int compareTo(), you should return 0 if the objects are equal, a negative number if other is greater than this and a positive number if other is smaller than this