collection之map

1.HashMap

代码语言：javascript复制

package learn.collection;

import org.testng.annotations.Test;
import org.w3c.dom.ls.LSOutput;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;

public class hashmap {

    private Map<String,String> createhashmap = new HashMap<>();

    public Map<String,String> createmap(){
        String key = "1";
        String value = "abc";
        String key2 = "c";
        String value2 = "123";
        String key3 = "b";
        String value3 = "d";
        createhashmap.put(key,value);
        createhashmap.put(key2,value2);
        createhashmap.put(key3,value3);
        return createhashmap;
    }

    @Test(groups = {"map"},priority = 0 )
    public void putmethod(){
        String key = "e";
        String value = "t";
        hashmap map = new hashmap();
        Map<String,String> newmap = map.createmap();
        System.out.println("使用put方法前" newmap);
        newmap.put(key,value);
        System.out.println("使用put方法后" newmap);
    }

    @Test(groups = {"map"},priority = 1)
    public void removemethod(){
        String key = "1";
        String delkey = "b";
        String delvalue = "d";
        hashmap map = new hashmap();
        Map<String,String> newmap = map.createmap();
        System.out.println("使用remove方法前" newmap);
        newmap.remove(key);
        System.out.println("使用remove方法后" newmap);
        System.out.println("去掉" delkey delvalue "前" newmap);
        newmap.remove(delkey,delvalue);
        System.out.println("去掉" delkey delvalue "后" newmap);
    }

    @Test(groups = {"map"},priority = 2)
    public void containsmethod(){
        hashmap map = new hashmap();
        Map<String,String> newmap = map.createmap();
        String containskey = "1";
        String containskey2 = "d";
        String containsvalue = "d";
        String containsvalue2 = "1235";
        boolean judge = newmap.containsKey(containskey);
        boolean judge2 = newmap.containsKey(containskey2);
        boolean judge3 = newmap.containsValue(containsvalue);
        boolean judge4 = newmap.containsValue(containsvalue2);
        if(judge){
            System.out.println(newmap "包含key:" containskey);
        }else{
            System.out.println(newmap "不包含key:" containskey);
        }

        if(judge2){
            System.out.println(newmap "包含key:" containskey2);
        }else{
            System.out.println(newmap "不包含key:" containskey2);
        }

        if(judge3){
            System.out.println(newmap "包含value:" containsvalue);
        }else{
            System.out.println(newmap "不包含value:" containsvalue);
        }

        if(judge4){
            System.out.println(newmap "包含value:" containsvalue2);
        }else{
            System.out.println(newmap "不包含value:" containsvalue2);
        }
    }

    @Test(groups = {"map"},priority = 3,description = "map迭代")
    public void iteratormethod(){
        hashmap map = new hashmap();
        Map<String,String> newmap = map.createmap();
        int size = newmap.size();
        System.out.println(newmap "长度为" size);
        Set<String> keyset = newmap.keySet();
        System.out.println(newmap "keyset为" keyset);
        for(Object o:keyset){
            System.out.println(o "值为：" newmap.get(o));
        }
    }

    @Test(groups = {"map"},priority = 4)
    public void newmethod(){
        hashmap newhashmap = new hashmap();
        Map<String,String> newmap = newhashmap.createmap();
        Set<Map.Entry<String, String>> es = newmap.entrySet();
        for(Map.Entry<String,String> e : es){
            System.out.println("Mapentry遍历：" e.getKey() e.getValue());
        }
        System.out.println(newmap "entrySet:" es);
        Set<String> ks = newmap.keySet();
        System.out.println(newmap "keySet:" ks);
    }
}

2.TreeMap

3.LinkedHashMap

hashmap treemap

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