Node.js 中的缓冲区是什么？

纯 JavaScript 非常适合 Unicode 编码的字符串，但它不能很好地处理二进制数据。当我们在浏览器级别对数据进行操作时没有问题，但在处理 TCP 流和对文件系统执行读写操作时需要处理纯二进制数据。为了满足这个需求，Node.js 使用了 Buffer，所以在本文中，我们将了解 Node.js 中的缓冲区。

Node.js 中的缓冲区：Node.js中的 Buffer 类用于对原始二进制数据执行操作。通常，Buffer 是指内存中的特定内存位置。缓冲区和数组有一些相似之处，但不同的是数组可以是任意类型，并且可以调整大小。缓冲区只处理二进制数据，不能调整大小。缓冲区中的每个整数代表一个字节。 console.log()函数用于打印 Buffer 实例。

对 Buffer执行操作的方法：

No	Method	Description
1	Buffer.alloc(size)	It creates a buffer and allocates size to it.
2	Buffer.from(initialization)	It initializes the buffer with given data.
3	Buffer.write(data)	It writes the data on the buffer.
4	toString()	It read data from the buffer and returned it.
5	Buffer.isBuffer(object)	It checks whether the object is a buffer or not.
6	Buffer.length	It returns the length of the buffer.
7	Buffer.copy(buffer,subsection size)	It copies data from one buffer to another.
8	Buffer.slice(start, end=buffer.length)	It returns the subsection of data stored in a buffer.
9	Buffer.concat([buffer,buffer])	It concatenates two buffers.

文件名：index.js

Javascript

// Different Method to create Buffer
var buffer1 = Buffer.alloc(100);
var buffer2 = new Buffer('GFG');
var buffer3 = Buffer.from([1, 2, 3, 4]);
 
// Writing data to Buffer
buffer1.write("Happy Learning");
 
// Reading data from Buffer
var a = buffer1.toString('utf-8');
console.log(a);
 
// Check object is buffer or not
console.log(Buffer.isBuffer(buffer1));
 
// Check length of Buffer
console.log(buffer1.length);
 
// Copy buffer
var bufferSrc = new Buffer('ABC');
var bufferDest = Buffer.alloc(3);
bufferSrc.copy(bufferDest);
 
var Data = bufferDest.toString('utf-8');
console.log(Data);
 
// Slicing data
var bufferOld = new Buffer('GeeksForGeeks');
var bufferNew = bufferOld.slice(0, 4);
console.log(bufferNew.toString());
 
// concatenate two buffer
var bufferOne = new Buffer('Happy Learning ');
var bufferTwo = new Buffer('With GFG');
var bufferThree = Buffer.concat([bufferOne, bufferTwo]);
console.log(bufferThree.toString());

使用以下命令运行index.js文件：

node index.js

输出：

Happy Learning
true
100
ABC
Geek
Happy Learning With GFG

参考： https://nodejs.org/api/buffer.html