Get numbers from string with PHP

Question

I have strings:

$one = 'foo bar 4 baz (5 qux quux)';
$two = 'bar baz 2 bar';
$three =  'qux bar 12 quux (3 foo)';
$four = 'foo baz 3 bar (13 quux foo)';

How can I find the numeric digits in these strings?

Maybe with function:

function numbers($string){

    // ???

    $first = ?;
    $second = ?;
}

For example:

function numbers($one){

    // ???

    $first = 4;
    $second = 5;
}

function numbers($two){

    // ???

    $first = 2;
    $second = NULL;
}

Best way for this maybe is regex, but how can I use this for my example? Maybe without regex?

You want to match only numerics? Not to convert one to 1 as well? — DaveRandom
– DaveRandom, Commented Jun 28, 2012 at 11:19
Your question is not clear, do you want to extract only numbers from a string? — Bud Damyanov
– Bud Damyanov, Commented Jun 28, 2012 at 11:19
Have a look at this... it will point you in direction... stackoverflow.com/questions/1077600/… — Brian
– Brian, Commented Jun 28, 2012 at 11:20
yes, i want to match only numerics. one, two etc are only examples words — Daniel Pairen
– Daniel Pairen, Commented Jun 28, 2012 at 11:24

DaveRandom · Accepted Answer · 2016-01-25 10:14:47Z

42

You can use regular expressions for this. The \d escape sequence will match all digits in the subject string.

For example:

<?php

function get_numerics ($str) {
    preg_match_all('/\d+/', $str, $matches);
    return $matches[0];
}

$one = 'foo bar 4 baz (5 qux quux)';
$two = 'bar baz 2 bar';
$three = 'qux bar 12 quux (3 foo)';
$four = 'foo baz 3 bar (13 quux foo)';

print_r(get_numerics($one));
print_r(get_numerics($two));
print_r(get_numerics($three));
print_r(get_numerics($four));

https://3v4l.org/DiDBL

edited Jan 25, 2016 at 10:14

answered Jun 28, 2012 at 11:23

DaveRandom

88.8k11 gold badges159 silver badges174 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Leri · Accepted Answer · 2012-06-28 11:21:36Z

7

You can do:

$str = 'string that contains numbers';
preg_match_all('!\d+!', $str, $matches);
print_r($matches);

answered Jun 28, 2012 at 11:21

Leri

12.6k7 gold badges46 silver badges60 bronze badges

Comments

Greg · Accepted Answer · 2014-10-14 14:22:15Z

5

Here's my attempt WITHOUT a regular expression

function getNumbers($str) {
    $result = array();

    // Check each character.
    for($i = 0, $len = strlen($str); $i < $len; $i++) {
        if(is_numeric($str[$i])) {
            $result[] = $str[$i];
        }
    }

    return $result;
}

$one = 'one two 4 three (5 four five)';
$two = 'one two 2 three';
$three =  'one two 12 three (3 four)';
$four = 'one two 3 three (13 four five)';

var_dump(getNumbers($one));
var_dump(getNumbers($two));
var_dump(getNumbers($three));
var_dump(getNumbers($four));

// Output:

array(2) {
  [0]=>
  string(1) "4"
  [1]=>
  string(1) "5"
}

array(1) {
  [0]=>
  string(1) "2"
}

array(3) {
  [0]=>
  string(1) "1"
  [1]=>
  string(1) "2"
  [2]=>
  string(1) "3"
}

array(3) {
  [0]=>
  string(1) "3"
  [1]=>
  string(1) "1"
  [2]=>
  string(1) "3"
}

edited Oct 14, 2014 at 14:22

answered Jun 28, 2012 at 11:23

Greg

22k17 gold badges89 silver badges110 bronze badges

1 Comment

DaveRandom Over a year ago

WITHOUT a regular expression - Admirable, but silly for this job. Regex will be much better/faster here - especially since you are calling strlen() on every iteration rather that caching in a variable the result once before the loop. Try this with a large string (or maybe even a small one) and you will find regex is much faster.

Collectives™ on Stack Overflow

Get numbers from string with PHP

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Linked

Related