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javacomparable

Comparable Class

I've been trying to learn the comparable class for sometime now, I know the correct syntax and the how it is used in most cases. Such as:

int result = ObjectA.compareTo(ObjectB);

would return a value of 0 if both object is the same; a negative value if object A is less then object B ,or a positive value if A is greater then B.

However when I go to actually write a program that uses the compareTo method, the compiler is saying that it can not find the compareTo method.

my question is: Do I have to directly inherit from the Comparable class in order to use the compareTo method? only reason I'm asking is because you do not have to explicitly inherit methods like toString or equals...because everything inherit from object. Where does CompareTo fall under?

Solution

  • You need to implement the Comparable interface:

    public class MyClass implements Comparable<MyClass>

    and then declare the compareTo() method:

    public int compareTo(MyClass myClass){
    //compare and return result
}