PHP: intval() equivalent for numbers >= 2147483647 - php

Question

In PHP 5, I use intval() whenever I get numbers as an input. This way, I want to ensure that I get no strings or floating numbers. My input numbers should all be in whole numbers. But when I get numbers >= 2147483647, the signed integer limit is crossed.
What can I do to have an intval() equivalent for numbers in all sizes?
Here's what I want to have:
<?php
$inputNumber = 3147483647.37;
$intNumber = intvalEquivalent($inputNumber);
echo $intNumber; // output: 3147483647
?>
Thank you very much in advance!
Edit: Based on some answers, I've tried to code an equivalent function. But it doesn't work exactly as intval() does yet. How can I improve it? What is wrong with it?
function intval2($text) {
$text = trim($text);
$result = ctype_digit($text);
if ($result == TRUE) {
return $text;
}
else {
$newText = sprintf('%.0f', $text);
$result = ctype_digit($newText);
if ($result == TRUE) {
return $newText;
}
else {
return 0;
}
}
}

Answer 1

Try this function, it will properly remove any decimal as intval does and remove any non-numeric characters.
<?php
function bigintval($value) {
$value = trim($value);
if (ctype_digit($value)) {
return $value;
}
$value = preg_replace("/[^0-9](.*)$/", '', $value);
if (ctype_digit($value)) {
return $value;
}
return 0;
}
// SOME TESTING
echo '"3147483647.37" : '.bigintval("3147483647.37")."<br />";
echo '"3498773982793749879873429874.30872974" : '.bigintval("3498773982793749879873429874.30872974")."<br />";
echo '"hi mom!" : '.bigintval("hi mom!")."<br />";
echo '"+0123.45e6" : '.bigintval("+0123.45e6")."<br />";
?>
Here is the produced output:
"3147483647.37" : 3147483647
"3498773982793749879873429874.30872974" : 3498773982793749879873429874
"hi mom!" : 0
"+0123.45e6" : 0
Hope that helps!

Answer 2

you can also use regular expressions to remove everything after the intial numeric parts:
<?php
$inputNumber = "3147483647.37";
$intNumber = preg_replace('/^([0-9]*).*$/', "\\1", $inputNumber);
echo $intNumber; // output: 3147483647
?>

Answer 3

Either use number_format($inputNumber, 0, '', '')
Or if you only want to check if its a whole number then use ctype_digit($inputNumber)
Don't use the proposed is_numeric, as also floats are numeric. e.g. "+0123.45e6" gets accepted by is_numeric

Answer 4

In addition to number_format, you can use sprintf:
sprintf("%.0f", 3147483647.37) // 3147483647
However, both solutions suffer from float overflow, for example:
sprintf("%.0f", 314734534534533454346483647.37) // 314734534534533440685998080

Answer 5

If you want to handle arbitrary-precision numbers, you will need to use the gmp extension. The function gmp_init(), for example, converts a string to a gmp resource object. the drawback is that you must use other functions of that extension to further process that object. Converting it back to a string is done using gmp_strval(), for example.
$gmpObject = gmp_init($string, 10);
if ($gmpObject === FALSE) {
# The string was not a valid number,
# handle this case here
}
echo gmp_strval($gmpObject);
You might want to only verify that the string is representing a valid number and use the string itself, if you do not intend to do any operations on the value. That can be done using a regular expression:
$containsInt = preg_match('/^\d+$/', $string);
# Or for floating point numbers:
$containsFloat = preg_match('/^\d+(.\d+)?$/', $string);
echo $string;
Another option is to use is_numeric(). But that function does more conversion than you might like. Quoting from docs of that function:
... +0123.45e6 is a valid numeric value ...

Answer 6

<?php
$a = 453453445435.4;
echo $bigint = floor($a);