Node basis _Buffer buffer

Buffer (Buffer)
         - Buffer array structure and the like, and a method of operation is also similar to an array
        - the array can not be stored in a binary file, and the Buffer is designed to store binary data
        - using the buffer does not require the introduction of a template, i.e., directly may be
        - are binary data stored in the buffer, but are displayed on the display 16 in the form of hexadecimal
            range of each element of the buffer is from 00 - FF 0 - 255
            00000000 - 11111111
 
            computer a 0 or a 1 we called a bit (bit)
 
            8bit = 1byte (bytes)
            1024byte 1KB =
            1024KB = 1MB
            1024MB = 1GB
            1024GB = 1TB
  
            element in the buffer, one byte of memory
 
           - Buffer size, once determined, can not be modified, Buffer is actually the direct operation of the underlying memory

  var STR = "Su Zai the Hello" ; 

  // a string stored into buffer 
  var buf = Buffer.from (STR); 

  the console.log (to buf.length); // The memory space 
  console.log (str. length); // string length 
  console.log (buf);

// Create a specified size Buffer 
// Buffer construct functions are not recommended 
var BUF2 = new new Buffer (10); // 10-byte Buffer 
the console.log (buf2.length);

//创建一个10个字节的buffer
var buf2 = Buffer.alloc(10);
//通过索引，来操作buf中的元素
buf2[0] = 88;
buf2[1] = 255;
buf2[2] = 0xaa;
buf2[3] = 255;

//只要数字在控制台或页面输出一定是10进制,toString可以转换进制
console.log(buf2[2].toString(16));

for(var i =0;i<buf2.length;i++){
    console.log(buf2[i]);
}

//Buffer.allocUnsafe(size)创建一个指定大小的buffer，但是buffer中可能含有敏感数据

var buf3 = Buffer.allocUnsafe(10);
console.log(buf3);


Buffer.from(str) 将一个字符串转换为buffer
Buffer.alloc(size) 创建一个指定大小的Buffer
Buffer.alloUnsafe(size) 创建一个指定大小的Buffer，但可能包含敏感数据
buf.toString() 将缓冲区中的数据转换为字符串

var buf4 = Buffer.from("我是一段文本数据");
console.log(buf4.toString());

注：具体操作用到Buffer缓冲区时，参考：http://nodejs.cn/api/buffer.html 官方文档查询使用方法

Node basis _Buffer buffer

Guess you like