PHP: Check if variable exist but also if has a value equal to something

Question

I have (or not) a variable $_GET[\'myvar\'] coming from my query string and I want to check if this variable exists and also if the value corresponds to somethi

Answer 1

As of PHP7 you can use the Null Coalescing Operator ?? to avoid the double reference:

$_GET['myvar'] = 'hello';
if (($_GET['myvar'] ?? '') == 'hello') {
    echo "hello!";
}

Output:

hello!

In general, the expression

$a ?? $b

is equivalent to

isset($a) ? $a : $b