How can I check that an array key exist if the array does not exist in PHP

Question

I am in a bind, multiple times on a page for different form items, I insert a css div class into a form item ONLY if an error_array key exists, this is how I highlight a form item that has an error in it.

Works, great if I have an error because then my error array is set, problem is before an error is set, it tries to look for an array key that does not exist. I was thinking using php's isset function first would be the ticket but I guess you cannot combine isset with another function?

---

<?php
//this works
$search_array = array('first' => 1, 'second' => 4);

if (array_key_exists('first', $search_array)){
    echo "good";
}


// this does not work, will give write errors
$search_array = array('first' => 1, 'second' => 4);

if (isset(array_key_exists('first', $search_array))){
    echo "good";
}

// Here is  1 example how I need to make the end result work
$country_class = (array_key_exists('country', $signup_errors)) ? ' signup_error' : ' signup_good';
echo '<select name="country" id="country" class="textarealong ' .$country_class. '"/>';
?>

In other parts I use it like this

<?PHP echo(array_key_exists('password', $signup_errors)) ? ' signup_error' : ' signup_good';?>

And I need to have it be a 1 line code if possible

Answer 1

If isset is false, the second statement wont get executed, because the parsers knows that both statements have to be true to get the whole statement true.

   $country_class = ( isset($signup_errors) && array_key_exists('country', $signup_errors)) ? ' signup_error' : ' signup_good';

BUT i would suggest you to initialize every variable you are using...

Answer 2

I'm not familiar enough with PHP syntax, but this sounds like a job for short-circuit evaluation, i.e. || or &&, where the second term is not evaluated if the first term alone can determine the result (if it's True in || or False in &&).