判断map类型不为空
时间: 2024-01-24 15:04:02 浏览: 75
要判断一个map类型是否为空,可以使用isEmpty()方法来进行判断。这个方法可以判断一个容器是否有元素。在Java中,我们可以通过调用map.isEmpty()来判断map是否为空。例如:
```
Map<String, String> map = new HashMap<String, String>();
System.out.println("map为空:" + map.isEmpty());
//加入元素
map.put("1", "1");
System.out.println("map为空:" + map.isEmpty());
```
在上述示例中,我们先创建了一个空的HashMap对象,然后通过调用isEmpty()方法来判断map是否为空。输出结果会根据是否有元素来进行判断。如果map为空,输出结果为true;如果map不为空,输出结果为false。<span class="em">1</span><span class="em">2</span><span class="em">3</span>
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