​x
 
<!DOCTYPE html>
<html>
<body>
​
<h1>JavaScript Set 对象</h1>
​
<p>创建一个 Set 并添加现有变量</p>
​
<p id="demo"></p>
​
<script>
function stringify(setObj)
{
  var setString = "Set 对象一共有 " + setObj.size + "个元素：";
  setObj.forEach( function( element ){
      setString += element + ", ";
  });
  return setString;
}
​
​
// 创建新的变量
const a = "a";
const b = "b";
const c = "c";
​
// 创建 Set
const letters = new Set();
​
// Add the values to the Set
letters.add(a);
letters.add(b);
letters.add(c);
​
​
// 打印
document.getElementById("demo").innerHTML = stringify( letters );
</script>
​
</body>
</html>