java map遍历

方法一：在for循环中遍历value

Map<String, String> map = new HashMap();
map.put("开发", "开发");
map.put("测试", "测试");
for (Object value : map.values()) {
System.out.println("第一种:" + value);
}
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方法二:：通过key遍历

for (String key: map.keySet()) {
System.out.println("第二种:" + map.get(key));
}
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方法三:：通过entrySet实现遍历

Set<Map.Entry<String, String>> entrySet = map.entrySet();
for (Map.Entry entry : entrySet) {
System.out.println("第三种:" + entry.getKey() + " ：" + entry.getValue());
}
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方法四:：通过Iterator迭代器实现遍历

Iterator<Map.Entry<String, String>> entryIterator = map.entrySet().iterator();
while (entryIterator.hasNext()) {
Map.Entry<String, String> entry = entryIterator.next();
System.out.println("第四种:" + entry.getKey() + " ：" + entry.getValue());
}
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方法五 ：通过lambda表达式进行遍历

map.forEach((key, value) -> {
System.out.println("第五种:" + key + " ：" + value);
});