PHP convert any value into a string? - php

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));
}
//...
}
?>

Answer 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)

Answer 2

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);

Answer 3

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.
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