###学习Buffer

打开命令行 node

Buffer

Buffer 是一个对象， 可用new 来实例化(构造函数)

new Buffer("你好, 我叫xxx")

new Buffer("你好, 我叫xxx", "base64")

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var buf = new Buffer(8)

buf.length // 8

超出长度的内容是不会被缓冲的

var buf = new Buffer('12345678')

console.log(buf)

// <Buffer 31 32 33 34 35 36 37 38>

var buf = new Buffer(7) buf.write('12345678') console.log(buf); // <Buffer 31 32 33 34 35 36 37>

var buf = new Buffer([1, 2, 3, 4]) console.log(buf) // <Buffer 01 02 03 04>

console.log(buf[1]) // 2

Buffer

{ [Function: Buffer] poolSize: 8192, isBuffer: [Function: isBuffer], compare: [Function: compare],
isEncoding: [Function], concat: [Function], byteLength: [Function] }

compare 用来判断两个Buffer的相对位置，处理按字符串的排序等 isEncoding 判断是否支持编码 concat 用于将几个Buffer 连接创建为一个Buffer byteLength 用来获得指定编码下字符串所占的字节数

Buffer实例方法

buffer[index] buffer.length buffer.write(string, offset=0, length, encoding='utf8') buffer.toString(encoding, start=0, end=buffer.length) buffer.copy(target, tStart, sStart, sEnd=buffer.length) buffer.slice(start, end) buffer.compare(otherBuffer) buffer.equals(otherBuffer) buffer.fill(value, offset, end)