Assign a default array element value if value is loosely equal to null

I am trying to add an if-else statement inside of an array.

Here is my code:

$excelData = array(
    $users->name,
    $users->first_name . ' ' . $organization->last_name,
    $users->user_email,
    date('d M y', $timestamp),
    if ($users->amount == NULL) {
        echo 0;
    } else {
        $users->amount;
    },
    if ($users->coupon_code == NUll) {
        echo "No Coupon Code";
    } else {
        $users->coupon_code;
    },
);

How do I set the default value if the normally accessed value is loosely equal to null?

If/else structures are not meant to be used in-line like that. They don't produce a value, but rather they perform an operation. What you're looking to do is have a single expression which produces a value. The ternary conditional operator can be used for that. (Scroll down on that link to the section titled "Ternary Operator".)

For example, this expression produces a value:

$users->amount == NULL ? 0 : $users->amount

It will evaluate to either 0 or $users->amount based on the condition. So in your code you would have:

$excelData = array(
    $users->name,
    $users->first_name . ' ' . $organization->last_name,
    $users->user_email,
    date('d M y', $timestamp),
    $users->amount == NULL ? 0 : $users->amount,
    $users->coupon_code == NULL ? "No Coupon Code" : $users->coupon_code
);