​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>JavaScript Map 对象</h1>
​
<p>可以将 Array 传递给 new Map() 构造函数</p>
​
<pre id="demo"></pre>
​
<script>
function stringify(mapObj)
{
  var mapString = "Map对象一共有 " + mapObj.size + "个元素：<br /><br />";
  mapObj.forEach( function( element , key ){
      mapString += JSON.stringify(key) + ":" + element + "<br />";
  });
  return mapString;
}
​
​
​
const apples = {name: 'Apples'};
const bananas = {name: 'Bananas'};
const oranges = {name: 'Oranges'};
​
// 创建新的 Map
const fruits = new Map([
  [apples, 500],
  [bananas, 300],
  [oranges, 200]
]);
​
​
document.getElementById("demo").innerHTML = stringify(fruits);
</script>
​
</body>
</html>