unset -- Clear a variable

Syntax: unset ?-nocomplain? ?--? ?name name name...?

Unsets one or more variables whose names are passed to the command. It does not matter whether the variables actually exist or not.

The -nocomplain option is ignored. The argument -- indicates the end of options; all arguments following -- will be treated as variable names whether they begin with a hyphen or not.

TCL Differences

In standard TCL, it's an error to unset a variable that doesn't exist; the command provides the -nocomplain option to cover this case. In Molt, unset never complains; the -nocomplain option is provided only for compatible with legacy TCL code. (Per the TCL Core Team, the -nocomplain option indicates, wherever it is found, that the original definition of the command got the default behaviour wrong.)