JavaScript 中的 Map.clear() 函数
javascripthtmlweb developmentfront end technology
Map 对象的 clear() 函数从当前 Map 对象中删除所有元素。
语法
其语法如下
mapVar.clear()
示例
<html>
<head>
<title>JavaScript 示例</title>
</head>
<body>
<script type="text/javascript">
var mapVar = new Map();
mapVar.set('1', 'Java');
mapVar.set('2', 'JavaFX');
mapVar.set('3', 'HBase');
mapVar.set('4', 'Neo4j');
var map = mapVar.clear();
document.write("Size of the map object: "+mapVar.size);
</script>
</body>
</html>
输出
Size of the map object: 0
示例
<html>
<head>
<title>JavaScript 示例</title>
</head>
<body>
<script type="text/javascript">
var mapVar = new Map();
mapVar.set('1', 'Raju');
mapVar.set('2', 'Ram');
mapVar.set('3', 'Rahim');
mapVar.set('4', 'Robert');
document.write("Size of the map: "+mapVar.size);
var map = mapVar.clear();
document.write("<br>");
document.write("Size of the map after clearing its contents using clear() function: "+mapVar.size);
</script>
</body>
</html>
输出
Size of the map: 4 Size of the map after clearing its contents using clear() function: 0
