buffer.writeUInt8()

buf.writeUInt8(value, offset[, noAssert])

Writes value to the Buffer at the specified offset. The value should be a valid unsigned 8-bit integer. Behavior is not defined when value is anything other than an unsigned 8-bit integer.

Set noAssert to true to skip validation of value and offset. This means that value may be too large for the specific function and offset may be beyond the end of the Buffer leading to the values being silently dropped. This should not be used unless you are certain of correctness.

Example:

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>