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@@ -0,0 +1,35 @@
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+/**
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+ * ES6提供的set 类似于数据中的数组
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+ * 可以用于扩展运算符 和 for of
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+ * set:
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+ * 1.size 返回集合中元素个数
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+ * 2.add() 增加一个新元素 返回当前集合
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+ * 3.delete() 删除元素 返回布尔值
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+ * 4.has() 检查元素中是否包含某个元素 返回布尔值
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+ * 5.clear() 清空集合 返回undefined
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+ */
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+
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+let s = new Set();
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+console.log(s);
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+let s1 = new Set([1,2,3,4,5,6,7,8]);
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+console.log(s1);
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+console.log(s1.size,'size');
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+console.log(s1.add(13),'add');
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+console.log(s1.delete(7),'delete');
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+console.log(s1.has(12),'has');
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+console.log(s1.clear(),'clear')
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+console.log(s1);
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+
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+var arr = [2,3,4,5,6,7,8,9];
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+var newArr = new Set(arr);
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+console.log(newArr,'newArr');
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+var newArr1 = Array.from(newArr);
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+console.log(newArr1,'newArr1');
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+
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+var arr1 = [1,2,2,345,67655,454,31,345,31,39,776,76,88,776];
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+// 去重
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+function reduction(arr) {
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+ let a = new Set(arr);
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+ return Array.from(a);
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+}
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+console.log(reduction(arr1));
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