[Java知识库]java集合判定元素

package collection;

import java.util.ArrayList;
import java.util.Collection;

/**
 *集合提供了判断是否包含给定元素的方法
 *boolean contains(E e) 
 */

public class ContainsDemo {
	public static void main(String[] args){
		Collection c = new ArrayList();
		c.add(new Point(1,2));
		c.add(new Point(2,5));
		c.add(new Point(6,1));
		c.add(new Point(5,2));
		c.add(new Point(3,2));
		
		System.out.println(c);
		
	}

}

package collection;
/*
 * 使用当前类实例作为集合元素。测试集合相关
 * 操作
 */
public class Point {
    private int x;
    private int y;
	public Point(int x, int y) {
		super();
		this.x = x;
		this.y = y;
	}
	public String toString(){
		return "("+x+","+y+")";
	}
}