buf.writeUInt8(value[, offset])

• value <integer> 要写入 buf 的数字。
• offset <integer> 开始写入之前要跳过的字节数。 必须满足 0 <= offset <= buf.length - 1。 默认值: 0。
• 返回: <integer> offset 加上写入的字节数。

将 value 写入 buf 中指定的 offset。 value 必须是有效的无符号 8 位整数。 当 value 不是无符号 8 位整数时，则行为未定义。

const buf = Buffer.allocUnsafe(4);

buf.writeUInt8(0x3, 0);
buf.writeUInt8(0x4, 1);
buf.writeUInt8(0x23, 2);
buf.writeUInt8(0x42, 3);

console.log(buf);
// 打印: <Buffer 03 04 23 42>

• value <integer> Number to be written to buf.
• offset <integer> Number of bytes to skip before starting to write. Must satisfy 0 <= offset <= buf.length - 1. Default: 0.
• Returns: <integer> offset plus the number of bytes written.

Writes value to buf at the specified offset. value must be a valid unsigned 8-bit integer. Behavior is undefined when value is anything other than an unsigned 8-bit integer.

const buf = Buffer.allocUnsafe(4);

buf.writeUInt8(0x3, 0);
buf.writeUInt8(0x4, 1);
buf.writeUInt8(0x23, 2);
buf.writeUInt8(0x42, 3);

console.log(buf);
// Prints: <Buffer 03 04 23 42>