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  • Map集合的四种遍历方式

    package com.xiaowu.map.demo;
    
    import java.util.HashMap;
    import java.util.Iterator;
    import java.util.Map;
    import java.util.Map.Entry;
    
    import org.junit.Test;
    
    /**
     * 
     * Map集合的四种遍历方式
     * 
     * 
     * @author WQ
     *
     */
    public class MapDemo {
    
        @Test
        public void Test() {
            Map<String, Object> map = new HashMap<String, Object>();
            for (int i = 0; i < 10; i++) {
                map.put("key" + i, "value" + i);
            }
            for (String i : map.keySet()) {
                Object object = map.get(i);
                System.out.println("object:" + object);
            }
        }
    
        @Test
        public void Test1() {
            Map<String, Object> map = new HashMap<String, Object>();
            for (int i = 0; i < 10; i++) {
                map.put("key" + i, "value" + i);
            }
            Iterator<Entry<String, Object>> it = map.entrySet().iterator();
            while (it.hasNext()) {
                Entry<String, Object> next = it.next();
                System.out.println(next.getKey() + "---------" + next.getValue());
            }
        }
    
        @Test
        public void Test2() {
            Map<String, Object> map = new HashMap<String, Object>();
            for (int i = 0; i < 10; i++) {
                map.put("key" + i, "value" + i);
            }
            for (Map.Entry<String, Object> entry : map.entrySet()) {
                System.out.println("key= " + entry.getKey() + " and value= "
                        + entry.getValue());
            }
        }
    
        @Test
        public void Test3() {
            Map<String, Object> map = new HashMap<String, Object>();
            for (int i = 0; i < 10; i++) {
                map.put("key" + i, "value" + i);
            }
            for (Object v : map.values()) {
                System.out.println("value= " + v);
            }
        }
    
    }
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  • 原文地址:https://www.cnblogs.com/mr-wuxiansheng/p/7010459.html
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