java

遍历Map的两种方法：keySet()和entrySet()

keySet是键的集合，Set里面的类型即key的类型
entrySet是键-值对的集合，Set里面的类型是Map.Entry

1.keySet()

1
2
3
4
5
6
7
8
9
10
Map map=new HashMap();
Iterator it=map.keySet().iterator();
Object key;
Object value;

while(it.hasNext()){
    key=it.next();
    value=map.get(key);
    System.out.println(key+":"+value);
}

2.entrySet()

1
2
3
4
5
6
7
8
9
10
11
Map map=new HashMap();
Iterator it=map.entrySet().iterator();
Object key;
Object value;

while(it.hasNext()){
    Map.Entry entry = (Map.Entry)it.next();
    key=entry.getKey();
    value=entry.getValue();
    System.out.println(key+"="+value);
}

也可以这么写：

1
2
3
4
5
for (Entry<String, Boolean> entry : map.entrySet()) {
    key=entry.getKey();
    value=entry.getValue();
    System.out.println(key+"="+value);
}