lovecoding
/
class


			
				
					
						
						
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							<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        var arr  = [1,2,3,4,56,78,4,3,1];
        var x = new Set(arr);
        console.log(x);
        console.log(x.size)
        // Set() 常用于数组去重
        // size 长度
        //  Array.from 将类数据转为数组
        var arr1 = Array.from(x);
        console.log(arr1);

        // 数组去重
        function fn1(aa) {
           return Array.from(new Set(aa));
        }
       console.log(fn1([3,4,5,434,2,11,34,4,3]));
        

       var a = new Set([1,2,3,4,12]);
        console.log(a);
        // add 添加
        console.log(a.add(99));
        // delete 删除  返回的是布尔值
        console.log(a.delete(1));
        a.delete(1);

        console.log(a);
    </script>
</body>
</html>