java collection study one

参考：原文地址

1.java collection  overview

 

2.Map  接口 概览

3、常用接口方法使用示例

add  remove  addAll  removeAll

package com.interview.base.collection;

import java.util.ArrayList;

import java.util.Collection;

import java.util.HashSet;

import java.util.Iterator;

import java.util.List;

import java.util.Set;

public class MyCollectionUtil {

public static void doSomething(Collection collection) {

Iterator iterator = collection.iterator();

while(iterator.hasNext()){

Object object = iterator.next();

//do something to object here...

}

}

public static void main(String[] args) {

String    anElement  = "an element";

String    twoElement  = "an element";

Collection setCollection = new HashSet();

Collection listCollection = new ArrayList();

boolean setChange = setCollection.add(anElement);

boolean setChange2 = setCollection.add(anElement);

System.out.println(setChange2);

System.out.println("setCollection: "+ setCollection.size());

System.out.println("contain test: " + setCollection.contains("aobo"));

boolean  removeExist = setCollection.remove(anElement);

boolean  removeNotExist = setCollection.remove("aobo");

System.out.println("removeExist: " + removeExist);

System.out.println("removeNotExist: " + removeNotExist);

boolean listChange = listCollection.add(anElement);

boolean listChange2 = listCollection.add(anElement);

System.out.println("listCollection: "+ listCollection.size());

// the first output method

for(Object s : listCollection){

System.out.println(s.toString());

}

//the secondn output  method

Iterator iterator = listCollection.iterator();

System.out.println("----------------------华丽分割线---------------------------------");

while(iterator.hasNext()){

Object object = iterator.next();

//do something to object;

System.out.println(object.toString());

}

}

}