Question

OK, first, this is very special problem. I was working on PHP for long time, and I don’t know why this happened.

I have a function adminUpdate. This function will return true. I set it always return true for testing.

Then I have function take that result.

static function result2JSON($result,$options = array()) {

        if($result == "permission") {
            echo "permission";
        }

        if($result == true) {
            echo "true";
        }


        switch ($result) {
            case 'permission':
                die($result."xxx permission");
                $json = self::setJSON("Permission");
                break;
            case 'exist':
                $json = self::setJSON("Exist");
                break;
            case false:
                $json = self::setJSON("Error");
                break;
            case "":
                $json = self::setJSON("Error");
                break;
            case 1 :
                $json = self::setJSON("OK");
                break;
            case true:
                $json = self::setJSON("OK");
                break;
            default:
                $json = self::setJSON("OK");
                break;
        }


        $json = array_merge($json,$options);


        return $json;

    }

These “Echo” use for testing on this case.
So, $result always = true before taken by this function.

But this is output I got:

permissiontrueResult = 1 IN permission section

That mean the $result = Permission , and then == true, and then == “permission” on switch.
Why is that ?

Answer 1

You may want to use identity check === rather than a check for equality.

In php, a non empty string is interpreted as true.

$result = "permission";
if($result)
     echo 'String interpreted as true';

Take a Look at Boolean page on php.net (Short) http://php.net/manual/en/language.types.boolean.php
and the PHP Comparison Operators page…
http://www.php.net/manual/en/language.operators.comparison.php