十六.Typed Array
Typed Array
支持基于任意字节的数据结构,以实现网络协议,加密算法,文件格式操作等。
ECMAScript 6
//ES6类相当于一下C结构
//例如:struct Example { unsigned long id; char username[16]; float amountDue }
class Example {
constructor (buffer = new ArrayBuffer(24)) {
this.buffer = buffer
}
set buffer (buffer) {
this._buffer = buffer
this._id = new Unit32Array (this.buffer, 0, 1)
this._username = new Unit8Array (this.buffer, 4, 16)
this._amountDue = new Float32Array (this._buffer, 20, 1)
}
get buffer () { return this._buffer }
set id (v) { this._id[0] = v }
get id () { return this._id[0] }
set username (v) { this._username[0] = v }
get username () { return this._username[0] }
set amountDue (v) { this._amountDue[0] = v }
get amountDue () {return this._amountDue[0] }
}
let example = new Example()
example.id = 7
example.username = "John Doe"
example.amountDue = 42.0
ECMAScript 5
//ES5中没有相应表达
// (only an equivalent in HTML5)