nodejs Node.js Buffer.readInt32BE()方法

Node.js Buffer.readInt32BE()方法

原文:https://www . geesforgeks . org/node-js-buffer-readint 32 be-method/

Buffer.readInt32BE()方法用于从给定偏移量的缓冲区对象中读取 32 位整数，并以大端字节顺序返回结果。

语法:

buffer.readInt32BE( offset )

参数:该方法接受单个参数偏移，指定缓冲对象的位置。它表示开始读取前要跳过的字节数。偏移值在 0 到缓冲区长度–4的范围内。默认值为 0。

返回值:该方法读取大端指定偏移量处的有符号 32 位整数。

例 1:

// Node.js program to demonstrate the
// buffer.readInt32BE() method 
const buff = Buffer.from([1, 2, 3, 4, 5]);

console.log(buff.readInt32BE(0));

console.log(buff.readInt32BE(1));

输出:

16909060
33752069

例 2:

// Node.js program to demonstrate the
// buffer.readInt32BE() method 
const buff = Buffer.from([1, 2, 3, 4, 5]);

console.log(buff.readInt32BE(4))

输出:

buffer.js:831
    throw new RangeError('Index out of range');
    ^

RangeError: Index out of range
    at checkOffset (buffer.js:831:11)
    at Buffer.readInt32BE (buffer.js:996:5)
    at Object. (/home/cg/root/8545664/main.js:8:18)
    at Module._compile (module.js:570:32)
    at Object.Module._extensions..js (module.js:579:10)
    at Module.load (module.js:487:32)
    at tryModuleLoad (module.js:446:12)
    at Function.Module._load (module.js:438:3)
    at Module.runMain (module.js:604:10)
    at run (bootstrap_node.js:389:7)

上面的示例显示了错误，因为它的参数不在有效范围内。

注意:

To get the value in small format, you can use the buffer.readint32le () method.
The above programs are compiled and run with the node index.js command.

参考:https://nodejs . org/API/buffer . html # buffer _ buf _ readint 32 be _ offset