~~NOTOC~~

====== -?varname (Exists) ======

===== Syntax =====

-?VARNAME

===== Description =====

Checks to see if a variable with name **VARNAME **exists (has been assigned). If so, 1 (true) is pushed to the stack else 0 (false).

===== Examples =====

<code 4rpl>
if (-?TheAnswer) # checks if the variable exists
    "We have the answer" Trace
else
    "We do not have the answer" Trace
endif
</code>