Comparable<t> and Comparato<t>

Same point:

Comparable<t> and comparator<t> are all interfaces.

Different points:

There are different methods for declaring them. The former is the CompareTo () method, and the latter is the Compare () method.

Comparable<t> this interface is implemented by a specific class of practical significance, indicating what sort method the object of this class has. The following Apple

 Public classAppleImplementsComparable<apple> {    /*** Weight of apples*/    Private intweight; /*** Natural sort is small to large * returns 1, which means that this object is larger than the parameter object and is in the back, so you can control descending or ascending order*/@Override Public intCompareTo (Apple apple) {if( This. Weight >apple.getweight ()) {            return-1; }        Else if( This. Weight <apple.getweight ()) {            return1; }        Else        {            return0; }    }
}

In the example above, Apple's light weight will be in the back, so it's sorted in descending order.

Comparator<t> This interface is typically used to define a comparer that is not implemented by a class that contains actual meaning, but rather by a specific comparer. The following defines a comparer:

 Public classWeightcomparatorImplementsComparator<apple> {    /*** Weight of apples*/    Private intweight; /*** Natural sort is from small to large * returns 1, which means this object is larger than the parameter object and is in front, so you can control descending or ascending order*/@Override Public intCompare (Apple A, Apple b) {if(A.getweight () >b.getweight ()) {            return1; }        Else if(A.getweight () <b.getweight ()) {            return-1; }        Else        {            return0; }    }         Public Static voidMain (string[] args) {Apple a=NewApple (); Apple b=NewApple (); Apple C=NewApple (); A.setweight (50); B.setweight (150); C.setweight (100); Apple[] Apples={A, B, c}; Arrays.sort (Apples,Newweightcomparator ()); // theSystem.out.println ("" + apples[0] + apples[1] + apples[2]); }}

The above example defines a weight comparator, which I use to compare the weight of an apple, i.e. using generics

public class Weightcomparator implements comparator<Apple>

Comparable<t> and Comparato<t>