diff --git a/JavaScript/BOM.md b/JavaScript/BOM.md
index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..7fb3e47f9f4d051700e3c3f55bb0098632152ca7 100644
--- a/JavaScript/BOM.md
+++ b/JavaScript/BOM.md
@@ -0,0 +1,4 @@
+1. windows
+2. onload
+3. 控制窗口大小
+4. 定时器
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diff --git a/JavaScript/javascript.md b/JavaScript/javascript.md
index 98c6276af157ddd6a205aa2bf573ec7fde377a9d..da64d721543b00a15d7797f6662b233c1d04b108 100644
--- a/JavaScript/javascript.md
+++ b/JavaScript/javascript.md
@@ -9,3 +9,4 @@
 ## [DOM](./DOM.md)
 ## BOM
 ## 事件
+## 作用域
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diff --git "a/JavaScript/\344\275\234\347\224\250\345\237\237.md" "b/JavaScript/\344\275\234\347\224\250\345\237\237.md"
new file mode 100644
index 0000000000000000000000000000000000000000..6cc1cf103601b3fbb3ead035782d78548d834e27
--- /dev/null
+++ "b/JavaScript/\344\275\234\347\224\250\345\237\237.md"
@@ -0,0 +1,65 @@
+全局作用域： 全局变量：全局作用域的变量  不用var声明的变量
+局部作用域： 局部变量：局部作用域的变量  形参
+````js
+fn();
+console.log(a);
+console.log(b);
+console.log(c);
+function fn(){
+    var a = b = c = 9; // => var a = 9; b = 9; c = 9;
+    //var a = 9,b = 9, c = 9; // => var a = 9,var b = 9, var c = 9;
+    console.log(a);
+    console.log(b);
+    console.log(c);
+}
+
+````
+块级作用域： {}
+
+作用域链：函数内部访问函数外部的变量，通过链式查找函数外部的变量。
+
+预解析：提升变量声明， 提升函数(局部作用域的变量声明也要提升)
+````js
+var num = 10;
+function fn(){
+    console.log(num);  //undefined
+    var num = 20;
+    console.log(num);  //20
+}
+fn();
+
+执行顺序 =>
+var num;
+function fn(){
+    var num;
+    console.log(num);
+    num = 20;
+    console.log(num);
+}
+num = 10;
+fn();
+````
+
+
+js对象
+1. {}  // json 对象
+2. new Object() 
+3. 构造函数  批量生成对象
+````
+function 构造函数(){
+    this.属性;
+    this.方法 = function(){};
+}
+new 构造函数();
+````
+
+new 
+1. 在栈中创造空的对象
+2. 指针指向栈中的对象
+
+遍历：
+for(var key in obj){
+
+}
+
+内置对象
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