php case no matches code example

Example 1: php switch

$age=20;
switch ($age) {
	case 19:
        echo "Age is 18";
        break;
    case 20:
        echo "Age is 20";
        break;
    case 21:
        echo "Age is 21";
        break;
}

Example 2: php switch 2 variables

switch ([$color, $size]) {
    case ['blue', 'small']:
        echo 'blue and small';
    break;

    case ['red', 'large'];
        echo 'red and large';
    break;
}