Extract a single integer from a string

Question

I want to extract the digits from a string that contains numbers and letters like:

"In My Cart : 11 items"

I want to extract the nu

Answer 1

I do not own the credit for this, but I just have to share it. This regex will get numbers from a string, including decimal points/places, as well as commas:

/((?:[0-9]+,)*[0-9]+(?:\.[0-9]+)?)/

Cited from here:
php - regex - how to extract a number with decimal (dot and comma) from a string (e.g. 1,120.01)?

Answer 2

Depending on your use case, this might also be an option:

$str = 'In My Cart : 11 items';
$num = '';

for ($i = 0; $i < strlen($str); $i++) {

    if (is_numeric($str[$i])) {
        $num .= $str[$i];
    }
}

echo $num; // 11

Though I'd agree a regex or filter_var() would be more useful in the stated case.

Answer 3

Follow this step it will convert string to number

$value = '$0025.123';
$onlyNumeric = filter_var($value, FILTER_SANITIZE_NUMBER_FLOAT, FILTER_FLAG_ALLOW_FRACTION);
settype($onlyNumeric,"float");

$result=($onlyNumeric+100);
echo $result;

Another way to do it :

$res = preg_replace("/[^0-9.]/", "", "$15645623.095605659");

Answer 4

Using preg_replace:

$str = '(111) 111-1111';
$str = preg_replace('/\D/', '', $str);
echo $str;

Output: 1111111111

Answer 5

Since there is only 1 numeric value to isolate in your string, I would endorse and personally use filter_var() with FILTER_SANITIZE_NUMBER_INT.

echo filter_var($string, FILTER_SANITIZE_NUMBER_INT);

A whackier technique which works because there is only 1 numeric value AND the only characters that come before the integer are alphanumeric, colon, or spaces is to use ltrim() with a character mask then cast the remaining string as an integer.

Demo

$string = "In My Cart : 11 items";
echo (int)ltrim($string, 'A..z: ');
// 11

---

If for some reason there was more than one integer value and you wanted to grab the first one, then regex would be a direct technique.

Demo

echo preg_match('/\d+/', $string, $m) ? $m[0] : '';

Answer 6

You can use preg_match:

$s = "In My Cart : 11 items";
preg_match("|\d+|", $s, $m);
var_dump($m);