Java学习——HashMap

Posted 2020-08-14

遍历

Map map = new HashMap(); 
Iterator iter = map.entrySet().iterator(); 
while (iter.hasNext()) { 
    Map.Entry entry = (Map.Entry) iter.next(); 
    Object key = entry.getKey(); 
    Object val = entry.getValue(); 

例

import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;

public class testMap {
    public static void main(String[] args){
        testMap test = new testMap();
        HashMap map = new HashMap<String, String>();
        map.put("a", "123");
        map.put("a", "456");
        map.put("b", "789");
        test.transMap(map);
    }
    void transMap(HashMap map){
        Iterator iter = map.entrySet().iterator();
        while(iter.hasNext()){
            Map.Entry entry =(Map.Entry)iter.next();
            Object key = entry.getKey();
            Object val = entry.getValue();
            System.out.println((String)key + ":" + (String)val);
        }
    }
}

输出

a:456
b:789

 

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