isset arrays

I'm trying to find out if a variable exists in an array.

So far I've tried using isset($a,$b) to find out if $a exists in the array $b but I get the same result every time under both circumstances.

I also tried using array_key_exists($a, $b) which also returned the same result.

Any ideas how I can find out if a variable exists within an array?

 

You want in_array. Array_key_exists is the same as going isset($array[$key]).

 

With in_array($a, $b) you can enter a third value which seems to be boolean. Does this mean you can run this command so that

if(in_array($a,$b,false)){
print "This was false";}

would return

This was false

if a was not in b?

 

The actual value.

in_array seems to do the trick. For some reason I was under the impression that in_array searches for the pattern rather than an identical match.