PHP convert any value into a string?

Question

Is there a way to convert any value especially boolean and arrays into strings? I want to do this for a cleaner error message in a function. Right now all I can get in this example below it this for an error message

Fatal error: Uncaught InvalidArgumentException: $argument cannot be in /file.php:## Stack trace: #0 /file.php:(##): myFunction(false) #1 {main} thrown in /file.php on line 47

I want it to say "$argument cannot be false" not "$argument cannot be "

<?php

myFunction(false);
myFunction(array('a', 'b'));

//Version 0.5
function myFunction($argument) {
    if (!is_string($argument)) {
        throw new InvalidArgumentException('$argument cannot be ' . strval($argument));
    }

    //...
}

?>

Would declaring a type be appropriate for your situation? function (string $argument) — Jared Farrish
– Jared Farrish, Commented Jul 31, 2020 at 18:04
(string)true === '1' and (string)false === ''. Welcome to PHP. — Sammitch
– Sammitch, Commented Jul 31, 2020 at 18:06
However, you can json_encode($argument) or gettype($argument) for a textual depiction or description of the value or type. — Jared Farrish
– Jared Farrish, Commented Jul 31, 2020 at 18:06
Typo: $argeument vs $arguement? Also swap '...'pair to a "...." pair? — HoldOffHunger
– HoldOffHunger, Commented Jul 31, 2020 at 18:07

Phiter · Accepted Answer · 2020-07-31 18:07:25Z

1

Best way to convert most value types to string is using json_encode.

An array for example would become ["a","b"].

Just json_encode($argument)

answered Jul 31, 2020 at 18:07

Phiter

15k14 gold badges52 silver badges87 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Jared Farrish Over a year ago

Note, this works for serializable content to some degree (a large array might be counter-productive to include). I would still recommend a type declaration for the function argument, enabling static checking for many scenarios, and omit defensive programming, a different discussion than the question asks..

bhutto54 Over a year ago

Thank you, this does the job.

AbraCadaver · Accepted Answer · 2020-07-31 18:24:37Z

0

I would use gettype and/or var_export:

throw new InvalidArgumentException('$argeument cannot be ' . gettype($argeument) . ' ' . var_export($argeument, true));

Or buffer output of var_dump and you can see it all:

ob_start();
var_dump($argeument);
$text = ob_get_clean();
throw new InvalidArgumentException('$argeument cannot be ' . $text);

edited Jul 31, 2020 at 18:24

answered Jul 31, 2020 at 18:18

AbraCadaver

79.2k7 gold badges75 silver badges91 bronze badges

Comments

Jared Farrish · Accepted Answer · 2020-07-31 18:39:16Z

Perhaps (in lieu of function (string $value), which I recommend)?

class InvalidArgumentType extends InvalidArgumentException
{
    public function __construct(int $position, string $requiredType, $value)
    {
        $encoded = json_encode($value);
        
        if (strlen($encoded) > 10) {
            $encoded = sprintf('%s ... %s', substr($encoded, 0, 10), substr($encoded, -1));
        }
        
        $inferredType = is_object($value) ? get_class($value) : gettype($value);
        
        parent::__construct(sprintf(
            'Argument %d value %s should be %s but is %s.',
            $position,
            $encoded,
            $requiredType,
            $inferredType
        ));
    }
}

class Foo {}

echo (new InvalidArgumentType(1, 'string', new Foo()))->getMessage().PHP_EOL;
echo (new InvalidArgumentType(2, 'string', [1,2,3,4,5,6,7,8,9,10]))->getMessage().PHP_EOL;
echo (new InvalidArgumentType(3, 'string', 123))->getMessage().PHP_EOL;
echo (new InvalidArgumentType(2, 'string', null))->getMessage();

Gives:

Argument 1 value {} should be string but is Foo.
Argument 2 value [1,2,3,4,5 ... ] should be string but is array.
Argument 3 value 123 should be string but is integer.
Argument 2 value null should be string but is NULL.

https://3v4l.org/ko7o1

Collectives™ on Stack Overflow

PHP convert any value into a string?

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

2 Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related