仓库源文，站点原文

title: 你所不知道的JavaScript数组 categories:

• JavaScript
• 前端杂烩 tags:
• tech
• cnblogs mark: hot warning: true date: 2014-03-03 01:56:00 fromUrl: http://www.cnblogs.com/hustskyking/archive/2014/03/03/javascript-array.html from: 博客园

[element0, element1, ..., elementN]
new Array(element0, element1, ..., elementN)
new Array(arrayLength)

"array".split("");
"array".match(/a|r/g);

var arr = [21, "李靖", new Date(), function(){}, , null];

    栈
+---------+                  堆
|   21    |         +-------------------+
+---------+         |                   |
|  "李靖" |         |                   |
+---------+         |  +--------+       |
| [refer] |----------->| Object |       |
+---------+         |  +--------+       |
| [refer] |----------------->+--------+ |
+---------+         |        |function| |
|undefined|         |        +--------+ |
+---------+         |                   |
|   null  |         +-------------------+
+---------+         Created By Barret Lee

var buffer  = new ArrayBuffer(30);

ArrayBuffer slice(
    unsigned long begin
    unsigned long end Optional
);

var buffer = new ArrayBuffer(12);
var x = new Int32Array(buffer);
x[1] = 1234;
var slice = buffer.slice(4);
var y = new Int32Array(slice);
console.log(x[1]);
console.log(y[0]);
x[1] = 6789;
console.log(x[1]);
console.log(y[0]);

<h4>2. 类型化数组</h4>

var x = new Float32Array(2);
x[0] = 17;
console.log(x[0]); // 17
console.log(x[1]); // 0
console.log(x.length); // 2

var x = new Float32Array([17, -45.3]);
console.log(x[0]);  // 17
console.log(x[1]);  // -45.29999923706055
console.log(x.length); // 2

var x = new Float32Array([17, -45.3]);
var y = new Float32Array(x);
console.log(x[0]); // 17
console.log(x[1]); //-45.29999923706055
console.log(x.length); // 2
x[0] = -2;
console.log(y[0]); // 17, y的值没变

var buffer = new ArrayBuffer(12);
var x = new Float32Array(buffer, 0, 2);
var y = new Float32Array(buffer, 4, 1);
x[1] = 7;
console.log(y[0]); // 7

       ArrayBuffer（12）
+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|1|2|3|4|5|6|7|8| | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+
\              /
  x (Float32Array)
  offset：0
  byteLength：4
  length:2

       ArrayBuffer（12）
+-+-+-+-+-+-+-+-+-+-+-+-+-+
|0|1|2|3|4|5|6|7|8| | | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+
        \       /
             y

      Created By Barret Lee

var buffer = new ArrayBuffer(12);
var x = new DataView(buffer, 0);
x.setInt8(0, 22);
x.setFloat32(1, Math.PI);
console.log(x.getInt8(0)); // 22
console.log(x.getFloat32(1)); // 3.1415927410125732

请求            响应
text            DOMString
arraybuffer     ArrayBuffer
blob            Blob
document        Document

var xhr = new XMLHttpRequest();
xhr.open('GET', '/path/to/image.png', true);
xhr.responseType = 'arraybuffer';

xhr.onload = function(e) {
    // this.response == uInt8Array.buffer
    var uInt8Array = new Uint8Array(this.response);
};

xhr.send();

<p>我们在 xhr.responseType 中设置了属性为 arraybuffer，那么在拿到的数据中就可以用类型化数组来接受啦！</p>

<h3>四、小结</h3>

<p>本文主要介绍了 Array 在堆栈模型中的存放方式，也详细描述了 ArrayBuffer 这个原始缓冲区的二进制数据类型，在 web 开发中，数据以及数据的储存是一个重要的部分，希望引起注意！</p>

<p>本文叙述上可能存在错误，请多多斧正！</p>

<h3>五、参考资料</h3>