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@@ -0,0 +1,45 @@
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+/**
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+ * ES6中提供的map 类似于对象 键值对的对象集合
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+ * 可以使用扩展运算符 和 for...of遍历
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+ * map:
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+ * 1.size 返回map的元素个数
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+ * 2.set() 增加一个新元素 返回当前Map
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+ * 3.get() 返回键名对象的键值
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+ * 4.has() 检查Map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 m = new Map();
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+console.log(m,'m');
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+let m1 = new Map([
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+ ["name","Lucy"],
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+ ["age","23"],
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+ ["sex","女"]
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+])
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+console.log(m1,'m1');
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+console.log(m1.size,'size');
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+console.log(m1.set("address","haErBin"));
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+console.log(m1.get("sex"))
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+console.log(m1.has("age"))
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+console.log(m1.clear());
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+console.log(m1,'mmm')
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+
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+var arr = [1,2,3,4,5];
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+let arr2 = arr.map((item,index) => {
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+ console.log(item,'item')
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+ console.log(index,'index')
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+})
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+
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+var a1 = new Map();
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+console.log(a1);
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+a1.set("obj",'aaa');
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+a1.set("list","bbb");
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+console.log(a1);
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+
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+
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+// entries（）
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+for(item of a1.entries()) {
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+ console.log(item,'aaa')
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+}
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+
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+console.log(a1)
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