LPC Library Functions: undefinedp

NAME

undefinedp() - determine whether or not a given variable is undefined.

SYNOPSIS

int undefinedp( mixed arg );

DESCRIPTION

Return 1 if `arg' is undefined. 'arg' will be undefined in the following cases:

• 'arg' is a variable set equal to the return value of a call_other to a non-existent method (e.g. arg = call_other(obj, "???")).
• 'arg' is a variable set equal to the return value for an element in a mapping that doesn't exist (e.g. arg = map[not_there]).
• 'arg' is a reference to a destructed object.
• 'arg' is an uninitialized variable.

undefinedp() is a synonym for nullp().

SEE ALSO

mapp(), stringp(), pointerp(), objectp(), intp(), bufferp(), floatp(), functionp(), nullp(), errorp()