Re: the if statement

[broomduster]

This looks like homework, so here are some hints.

(keys %hash) is a list of the keys for %hash. The scalar assignment $input = (keys %hash) puts the number of keys into $input (which is probably not what you want to do). OTOH, to compare $input to each of the keys, you need to loop through the keys, comparing $input to each key. Since the keys (and the user input) are strings, you use eq to do the comparison.

Updated: Scrub the stupidity; no need to check everything; this is a hash, after all.

[eyepopslikeamosquito]

you need to loop through the keys, comparing $input to each key

Doing linear scans over an associative array is like trying to club someone to death with a loaded Uzi. :-)

-- Larry Wall in Authoritative list of Larry Wall quotes

See also Clubbing someone to death with a loaded Uzi blog by Dominus.

[FunkyMonk]

you need to loop through the keys, comparing $input to each key

That's what exists is for. In this case if ($hash{$input}) { ... } is probably good enough.