Is it possible in php to turn string var into type name?

Question

So, can I get this code working:

    $typename='integer';
    $tmp='12321321312';
    $var=($typename)$tmp;

WITHOUT using conditions, like:

    if($typename=='integer')
        $var=(integer) $tmp;

AND WITHOUT using evals, like:

   eval( '$var=(' . $typename . ') $tmp;' );

Community · Accepted Answer · 2023-11-17 20:33:26Z

2

You can use settype.

$typename = 'integer';
$tmp = '12321321312'; // $tmp will be passed as a reference
settype($tmp, $typename);

// $tmp is now an integer

Possibles values of type are:

"boolean" (or, since PHP 4.2.0, "bool")
"integer" (or, since PHP 4.2.0, "int")
"float" (only possible since PHP 4.2.0, for older versions use the deprecated variant "double")
"string"
"array"
"object"
"null" (since PHP 4.2.0)

CommunityBot

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answered Nov 26, 2013 at 17:27

swatkins

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2 Comments

Thank you. It works perfectly. To my shame I was unable to make up a correct search query to find this function.

That's great! You're welcome. I would've searched something like "dynamic type casting".

Community · Accepted Answer · 2023-11-17 20:38:18Z

1

Yes, it is possible using anonymous functions (available on PHP versions => 5.3.0).

$typename = 'intval';
$tmp = '2323';
$var = $typename($tmp); // <= note the syntax difference
var_dump($var);

Output:

int(2323)

CommunityBot

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answered Nov 26, 2013 at 17:27

Amal

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Great solution, however (IMHO) settype() is far more convenient, because the name of function tells what it does. Clear code == good code.