# bin/set-u16-be
Return a copy of `$bytes` with an unsigned 16-bit integer
written at `offset` (big-endian).
Byte strings are immutable — the original `$bytes` is unchanged.
## Syntax
[bin/set-u16-be $bytes $offset $value]
## Parameters
- `$bytes` — byte string to copy and write into
- `$offset` — 0-based byte offset
- `$value` — value to write; clamped to the 16-bit range and truncated toward zero
## Examples
def buf [bin/set-u16-be [bin/zeros 2] 0 513] [bin/u16-be-at $buf 0] # → 513 [bin/u8-at $buf 0] # → 2
## Returns
New byte string. A negative or out-of-bounds offset returns `%Err{:message}`.
## See Also
`bin/u16-be-at`, `bin/set-u16`, `bin/set-bytes`, `bin/bytes`