初识JAVA：Java类库之比较器（重点）

public interface Comparable<T> {
	public int compareTo(T o);
}

package com.pku.wuyu.io;
import java.util.Arrays;
class Person implements Comparable <Person> {
	private String name ;
	private int age ;
	public Person(String name,int age) {
		this.name = name ;
		this.age = age ;
	}
	@Override
	public String toString() {
		return "Person [name=" + name + ", age=" + age + "]\n";
	}
	@Override
	public int compareTo(Person o) {
		if (this.age > o.age) {
			return 1;
		} else if (this.age < o.age) {
			return -1;
		} else {
			return 0;
		}
	}
}
public class Demo01 {
	public static void main(String[] args) throws Exception {
		Person per[] = new Person[] { new Person("张三", 20),
				new Person("李四", 19), new Person("王五", 21) };
		Arrays.sort(per) ;	// 排序
		System.out.print(Arrays.toString(per));
	}
}