guard

Control flow

If the condition is false, the else block runs (usually return). Early-out, not an if replacement.

Syntax

guard (condition) else {
    warn("…");
    return;
}

Parameters

Name	Type	Description
condition	bool	Must be true to continue.

Return value

None. The else block typically returns.

Luau emit

if not (condition) then … end

Description

The else is required. After a successful guard, the compiler (and the reader) treat the condition as established — e.g. player != null.

Example

guard (player != null) else {
    warn("Invalid player");
    return;
}
post(player.Name);

Emits:

if not (player ~= nil) then
  warn("Invalid player")
  return
end
print(player.Name)

See also

if · null · match