NodeJS基础入门-Buffer

Buffer.byteLength

console.log(Buffer.byteLength('test'));

console.log(Buffer.byteLength('我是C语言爱好者'));

每个中文是3个字节

Buffer.isBuffer

console.log(Buffer.isBuffer({}));

console.log(Buffer.isBuffer(Buffer.from([1,2,3])));

Buffer.concat()

const buf1 = Buffer.from('This ');

const buf2 = Buffer.from('is ');

const buf3 = Buffer.from('a ');

const buf4 = Buffer.from('book ');

console.log(Buffer.concat([buf1, buf2, buf3, buf4]).toString());

实例的常见用法

buf.length

const buf = Buffer.from('你好');

console.log(buf.length);

const buf2 = Buffer.alloc(10);

buf2[0] = 2;

console.log(buf2.length);

buf.toString()

console.log(buf.toString());

console.log(buf.toString('base64'));

buf.fill()

const buf3 = Buffer.allocUnsafe(10);

console.log(buf3);

console.log(buf3.fill(10,2,6));

buf.equals()

const buf = Buffer.from('test');

const buf2 = Buffer.from('test');

const buf3 = Buffer.from('test!');

console.log(buf.equals(buf2));

console.log(buf.equals(buf3));

比较两个内容是否一样：

buf.indexOf()

const buf = Buffer.from('test');

console.log(buf.indexOf('es'));

console.log(buf.indexOf('esa'));

Buffer乱码问题的解决

const buf = Buffer.from('中文字符串！');

for (let i = 0; i < buf.length; i += 5) {

  const b = Buffer.allocUnsafe(5);

  buf.copy(b, 0, i);

  console.log(b.toString());

}

输出是乱码：

输出存在乱码

const StringDecoder = require('string_decoder').StringDecoder;

const decoder = new StringDecoder('utf8');

const buf = Buffer.from('中文字符串！');

for (let i = 0; i < buf.length; i += 5) {

  const b = Buffer.allocUnsafe(5);

  buf.copy(b, 0, i);

  console.log(decoder.write(b));

}