PHP : Convert(cast) string to bigInt

Problem :

In PHP, you want to convert(cast) a string to become big integer value.

Solution :

Use GNU Multiple Precision's gmp_intval() function to convert the string to a big integer value.

For example :

 <?php

 $str = "123456789123456789";
 $bigInt = gmp_init($str);

 $bigIntVal = gmp_intval($bigInt);
 echo $bigIntVal."\n";

 ?>

Output :

123456789123456789

Notes :

See http://php.net/manual/en/gmp.installation.php on how to get GMP installed on your server.

Reference :

http://php.net/manual/en/book.gmp.php

http://php.net/manual/en/function.gmp-intval.php