array_key_exists behavior

[ennemkay]

Hi,

 

Just wondering if someone can explain to me how this code works:

 

 

if (array_key_exists('a',array('a'))) { echo 'yes'; }

 

 

The "if" predicate doesn't evaluate to "true" as I expected, and I'm trying to understand why. TIA

[Muddy_Funster]

you are not setting the array key to 'a', you are setting the value of the array key 0 to 'a'. thus you shouldn't be getting true. test with

if(array_key_exists('a', array('a'=>'this is the value'))){echo "yay!, found it";}

[salathe]

The array_key_exists() function returns whether the array has the specified key, or not. To steal a comment from the manual, "An array in PHP is … a type that associates values to keys." (http://php.net/arrays). In your example, your array has only one value "a" and its key is 0.

 

It looks like the function you really wanted was in_array() (http://php.net/in_array), which returns whether the array as the specified value, or not.