node Buffer缓存区常见操作示例

本文实例讲述了node buffer缓存区常见操作。分享给大家供大家参考，具体如下：

创建buffer类

var buf=new buffer(10);
var buf=new buffer([10,20,30,40]);
var buf=new buffer("www.baidu.com","utf-8");

写入缓存区

buf.write(string[,offset[,length]][encoding])
buf=new buffer(256);
len=buf.write("www.baidu.com")
console,log("写入字节数："+len)

从缓存读取数据

buf.tostring([encoding[,start[,end]]])
buf=new buffer(26);
for(var i=0;i<26;i++;){
buf[i]=i+97;
}
console.log(buf.tostring('ascill'));
console.log(buf.tostring('ascill',0,5))
console.log(buf.tostring('utf-8',0,5))
console.log(buf.tostring('undefined',0,5))

转为json

buf.tojson()
var buf=new buffer('www.baidu.com');
var json=buf.tojson('buf')
console.log(json)

缓存合并

buffer.concat(list[,totallength]);
var buffer1=new buffer('百度搜索');
var buffer2=new buffer('www.baidu.com');
var buffer3=buffer.concat([buffer1,buffer2]);
console.log("buffer3内容"+buffer3.tostring())

缓存区比较

buf.compare(otherbuffer)
var buffer1=new buffer('abc');
var buffer2=new buffer('abcd');
var result=buffer1.compare(buffer2);
if(result<0){
console.log(buffer1+"在"+buffer2+"之前")
}else if(result==0){
console.log(buffer1+"等于"+buffer)
}else{
console.log(buffer1+"在"+buffer2+"之后")
}

拷贝缓存区

buf.copy(targetbuffer[,targetstart[,sourcestart[,sourcend]]])
var buffer1=new buffer('abc');
var buffer2=new buffer(3);
buffer1.copy(buffer2);
console.log("buffer2 content:"+buffer2.tostring())

缓存区裁剪

buf.slice([start[,end]])
var buffer1=new buffer('baidu')
var buffer2=buffer1.slice(0,2);
console.log("buffer2 content:"+buffer2.tostring());
buffer2 content:ba

缓存区长度

buf.length
var buffer=new buffer("www.baidu.com");
console.log("buffer length:"+buffer.length)
buffer length:13

希望本文所述对大家node.js程序设计有所帮助。