Node.js Buffer.readBigUInt64LE() 方法
Buffer.readBigUInt64LE() 方法用于从给定偏移量的缓冲区对象中读取无符号 64 位整数,并以小端序返回结果。
句法:
buffer.readBigInt64LE( offset )
参数:此方法接受一个指定缓冲区对象位置的参数偏移量。它表示开始读取之前要跳过的字节数。 offset 的值在0 到 buffer.length – 8的范围内。默认值为 0。
返回值:此方法在 Little endian 的指定偏移处读取一个无符号的 64 位整数。
示例 1:
文件名:index.js
javascript
// Node.js program to demonstrate the
// buffer.readBigUInt64LE() method
const buff = Buffer.from([0x00, 0x00,
0x0e, 0x00, 0xff, 0xff, 0xff, 0xff]);
// Getting big integer value by
// using readBigUInt64LE method
const value = buff.readBigUInt64LE(0);
// Display the result
console.log("Big Integer :- " + value);
javascript
// Node.js program to demonstrate the
// buffer.readBigUInt64LE() method
const buff = Buffer.from([0x00, 0x00,
0x0e, 0x00, 0xff, 0xff, 0xff, 0xff]);
// Getting big integer value by
// using readBigUInt64LE method
const value = buff.readBigUInt64LE(1);
// Display the result
console.log("Big Integer :- " + value);
使用以下命令运行index.js文件:
node index.js
输出:
Big Integer :- 18446744069415501824
示例 2:
文件名:index.js
javascript
// Node.js program to demonstrate the
// buffer.readBigUInt64LE() method
const buff = Buffer.from([0x00, 0x00,
0x0e, 0x00, 0xff, 0xff, 0xff, 0xff]);
// Getting big integer value by
// using readBigUInt64LE method
const value = buff.readBigUInt64LE(1);
// Display the result
console.log("Big Integer :- " + value);
使用以下命令运行index.js文件:
node index.js
输出:
internal/buffer.js:77
throw new ERR_OUT_OF_RANGE(type || 'offset',
^
RangeError [ERR_OUT_OF_RANGE]: The value of "offset" is out of range. It must be >= 0 and
<= 0. Received 1
at boundsError (internal/buffer.js:77:9)
at Buffer.readBigUInt64LE (internal/buffer.js:88:5)
at Object. (F:\java\GFG.js:7:20)
at Module._compile (internal/modules/cjs/loader.js:1138:30)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:1158:10)
at Module.load (internal/modules/cjs/loader.js:986:32)
at Function.Module._load (internal/modules/cjs/loader.js:879:14)
at Function.executeUserEntryPoint [as runMain] (internal/modules/run_main.js:71:12)
at internal/main/run_main_module.js:17:47 {
code: 'ERR_OUT_OF_RANGE'
}
上面的示例显示了错误,因为它的参数不在有效范围内。
参考: https://nodejs.org/dist/latest-v12.x/docs/api/buffer.html#buffer_buf_readbiguint64le_offset