PHP is_null() VS isset() VS empty() cheat sheet

Because sometimes things aren’t so obvious, I decided to share my true table.

• is_null – Finds whether a variable is NULL
• isset – Determine if a variable is declared and is different than NULL
• empty – Determine whether a variable is empty
• isEmpty() – Determine whether a variable is empty (0 and “0” are considered not empty)
• if () – The if statement

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isEmpty()

Does PHP’s empty() function confuse you? I am now using isEmpty() and it seems to work fine (0 and “0” are considered not empty).

/**
 * Helper class | General-purpose utility class
 */
class Helper
{
    /**
     * Determine whether a variable is empty.
     * 0 and "0" are considered not empty.
     *
     * @param mixed $value Value to be checked.
     *
     * @return boolean
     */
    public static function isEmpty(&$value): bool
    {
        if ($value === 0 || $value === '0') {
            return false;
        }

        return !$value;
    }
}

See example on repl.it at https://repl.it/@SandroMiguel/isset-vs-isnull-vs-empty

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