66 lines
1.4 KiB
Markdown
66 lines
1.4 KiB
Markdown
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# HHHHH终于来到了js
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=== 绝对等于 长得一样 数据类型也要一样
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== 等于 但是 如果字符串的 111 与int 的111 是相等的
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console.log(X) ->打印X
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NAN not a number NAN===NAN false 只能通过isNAN(X)来判断
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```js
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var person = {
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name: '张三',
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age: 30,
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greet: function() {
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console.log('你好，我是' + this.name);
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}
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};
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```
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## Arrylist
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```js
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arr.push( 可以填入多个)从后面 arr.unshift()从前面加
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arr.pop()出去最后一个 arr.shift()从前面减去
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```
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## 属性 动态删除属性
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```js
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delete peroson.name
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person.hasdhoa="dasdsa" 就这么动态的增加属性了
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```
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## 所有键的类型都是用字符串表示
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```js
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"age" in person true
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"toString" in person true 还可以看父级的东西
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person.hasOwnProperty() 看自身有的
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```
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## 循环
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```
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for (let n of arr){
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输出聂荣
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}
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for(let n in arr){
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输出下标
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}
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```
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所有的变量都是绑定在window下 方法也是
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## DOM
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将html中的各个元素 封装成为了对象
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