node Buffer緩存區常見操作示例

這篇文章主要介紹了node Buffer緩存區常見操作,涉及node.js操作Buffer緩存的創建、寫入、讀取、轉換等相關實現技巧,需要的朋友可以參考下

本文實例講述了node Buffer緩存區常見操作。分享給大家供大家參考，具體如下：

創建buffer類

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

寫入緩存區

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

從緩存讀取數據

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))

轉爲json

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

緩存合併

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內容"+buffer3.toString())

緩存區比較

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+"等於"+buffer)
}else{
console.log(buffer1+"在"+buffer2+"之後")
}

拷貝緩存區

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())

緩存區裁剪

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

緩存區長度

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

希望本文所述對大家node.js程序設計有所幫助。