Question

I have an array that’s accessed via $request (this is not the same as $_REQUEST). The array print_r’s out as

Array
(
    [num_days] => 30
    [customer_id] => 5
)

The num_days key may or may not exist (it can be any number of things.) I need to test to see if the key exists. I’ve tried this:

if(array_key_exists($request['num_days'], $request)) {
    echo "num_days exists";
}
else {
    echo "num_days doesn't exist";
}

This always hits the else. Am I doing this wrong? Is num_days not considered a key? If not, how can I test for the existence of that element (NOT the value of it, but whether it exists at all)?

Answer 1

What you have done is wrong

array_key_exists — Checks if the given key or index exists in the array

Your code with array_key_exists Read more

if(array_key_exists('num_days', $request)) {
    echo "num_days exists";
}
else {
    echo "num_days doesn't exist";
}

Alternative method with isset Read more

   if(isset($_REQUEST['num_days'])) {
        echo "num_days exists";
    }
    else {
        echo "num_days doesn't exist";
    }