Update JavaScript_基础.md

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@ -87,7 +87,7 @@ alert(stringValue.substr(3, 7)); // "lo worl"
// 当第一个参数为负值时 // 当第一个参数为负值时
alert(stringValue.slice(-3)); // "rld" 按照规则等价于: slice(8) alert(stringValue.slice(-3)); // "rld" 按照规则等价于: slice(8)
alert(stringValue.substring(-3)); // "hello world" 按照规则等价于: substring(0) alert(stringValue.substring(-3)); // "hello world" 按照规则等价于: substring(0)
alert(stringValue.substr(-3)); // "rld" 按照规则等价于: substr(8) alert(stringValue.substr(-3)); // "rld" 按照规则等价于: substr(8)
// 当第二个参数为负值时 // 当第二个参数为负值时
@ -236,9 +236,9 @@ var colors = ["red", "blue", "green"];
```javascript ```javascript
var colors = ["red", "blue", "green"]; var colors = ["red", "blue", "green"];
colors.length = 2; // ["red", "blue"] colors.length = 2; // ["red", "blue"]
colors[colors.length] = "green"; // ["red", "blue", "green"] colors[colors.length] = "green"; // ["red", "blue", "green"]
colors[10] = "black"; // ["red", "blue", "green", empty × 7, "black"] colors[10] = "black"; // ["red", "blue", "green", empty × 7, "black"]
``` ```
数组的其他常用方法如下: 数组的其他常用方法如下:
@ -269,8 +269,8 @@ ECMAScript 的数组提供了类似栈的特性,能够实现后进先出:
var colors = ["red", "blue", "green"]; var colors = ["red", "blue", "green"];
colors.push("black"); // ["red", "blue", "green", "black"] colors.push("black"); // ["red", "blue", "green", "black"]
colors.pop() // "black" colors.pop() // "black"
colors // ["red", "blue", "green"] colors // ["red", "blue", "green"]
``` ```
**4. 队列方法** **4. 队列方法**
@ -278,9 +278,9 @@ colors // ["red", "blue", "green"]
CMAScript 的数组提供了类似栈的特性,能够实现先进先出: CMAScript 的数组提供了类似栈的特性,能够实现先进先出:
```javascript ```javascript
colors.push("black","yellow"); // ["red", "blue", "green", "black", "yellow"] colors.push("black","yellow"); // ["red", "blue", "green", "black", "yellow"]
colors.shift() // "red" colors.shift() // "red"
colors // ["blue", "green", "black", "yellow"] colors // ["blue", "green", "black", "yellow"]
``` ```
**5. 重排序方法** **5. 重排序方法**
@ -330,11 +330,11 @@ splice() 用于删除并在删除位置新增数据项,它接收任意个参
```javascript ```javascript
var colors = ["red", "green", "blue", "yellow"]; var colors = ["red", "green", "blue", "yellow"];
colors.splice(1,2) // 返回删除的数据项:["green", "blue"] colors.splice(1,2) // 返回删除的数据项:["green", "blue"]
colors // ["red", "yellow"] colors // ["red", "yellow"]
colors.splice(1,0,"black","green") // [] colors.splice(1,0,"black","green") // []
colors // ["red", "black", "green", "yellow"] colors // ["red", "black", "green", "yellow"]
``` ```
**7. 位置方法** **7. 位置方法**