Check if a switch statement is true

Question

I wanted to check if my switch statement is true and if it is, I want to do something with it. e.g.

$a = trim($_POST['code']);

    switch ($a) {
    case "123";
        break;
    case "467";
        break;
    default : "incorrect";
    }

I then want to do an if statement like this

if(switch == true) {
    $a = trim($_POST['code']);
}
else {
$Error ="incorrect code";
$hasError = true;
}

if(switch == true) is not right. How will I check if the switch statement is true?

Thanks for your time.

Answer 1

A switch statement is not an expression and thus cannot be "true". You can only use a switch statement for side-effects, such as assigning a variable.

For instance (fixing the syntax errors)

$valid = false; # default to false

switch ($a) {
    case "123":
    case "467":
        $valid = true; # yay, "valid!"
        break;
    default:
        break;
}

if ($valid === true) {
  # ..
}

Although, in practice, I would rarely write code that looked like that - just do the action in the switch or use the if-statement directly; use a function, perhaps containing the switch-statement to write cleaner code.

function isValid($secretCode) {
  switch ($secretCode) {
    case "123":
    case "467":
      return true;
    default:
      return false;
  }
}

if (isValid($a)) {
  # ..
}

Answer 2

The case keyword ends with a :(colon) and not with a ; (semicolon)

Answer 3

I'd go in a complete opposite direction and use in_array instead:

//If trim($_POST['code']) is either 123 or 467 then..
if ( in_array( trim( $_POST['code'] ), array("123", "467") ) {
    echo 'Correct!';
} else {
    echo 'Incorrect!';
}

Answer 4

$a = trim($_POST['code']);
$hasError = 0;

switch ($a) {
    case "123":
    break;

    case "467":
    break;

    default : 
        $hasError = 1;
    break;
}

Answer 5

Your code should be like this :

    $a = trim($_POST['code']);

    switch ($a) {
    case "123":
        break;
    case "467":
        break;
    default : "incorrect";
    }

replace : (colon) with ; (semicolon).

Answer 6

$switch_true = true;
switch($a){
    case 123: break; // $switch_true stays true
    case 267: break; // $switch_true stays true
    // for any other value
    default: $switch_true = false; break; // $switch_true becomes false
}
var_dump($switch_true);

More about switch here.

But you should use:

$switch_true = in_array($a, array(123, 267));

Switch is not really meant for this kind of use.