Regex Help with manipulating string

Question

Hi, i am seriously struggling to get my head around regex.

I have a sring with "iPhone: 52.973053,-0.021447"

i want to extract the two numbers after the colon into two seperate strings so delimited by the comma.

Can anyone help me? Cheers

Answer 1

Try:

preg_match_all('/\w+:\s*(-?\d+\.\d+),(-?\d+\.\d+)/',
    "iPhone: 52.973053,-0.021447 FOO: -1.0,-1.0",
    $matches, PREG_SET_ORDER);
print_r($matches);

which produces:

Array
(
    [0] => Array
        (
            [0] => iPhone: 52.973053,-0.021447
            [1] => 52.973053
            [2] => -0.021447
        )

    [1] => Array
        (
            [0] => FOO: -1.0,-1.0
            [1] => -1.0
            [2] => -1.0
        )

)

Or just:

preg_match('/\w+:\s*(-?\d+\.\d+),(-?\d+\.\d+)/',
    "iPhone: 52.973053,-0.021447",
    $match);
print_r($match);

if the string only contains one coordinate.

A small explanation:

\w+      # match a word character: [a-zA-Z_0-9] and repeat it one or more times
:        # match the character ':'
\s*      # match a whitespace character: [ \t\n\x0B\f\r] and repeat it zero or more times
(        # start capture group 1
  -?     #   match the character '-' and match it once or none at all
  \d+    #   match a digit: [0-9] and repeat it one or more times
  \.     #   match the character '.'
  \d+    #   match a digit: [0-9] and repeat it one or more times
)        # end capture group 1
,        # match the character ','
(        # start capture group 2
  -?     #   match the character '-' and match it once or none at all
  \d+    #   match a digit: [0-9] and repeat it one or more times
  \.     #   match the character '.'
  \d+    #   match a digit: [0-9] and repeat it one or more times
)        # end capture group 2

Answer 2

A solution without using regular expressions, using explode() and stripos() :) :

$string = "iPhone: 52.973053,-0.021447";
$coordinates = explode(',', $string);
// $coordinates[0] = "iPhone: 52.973053"
// $coordinates[1] = "-0.021447"

$coordinates[0]  = trim(substr($coordinates[0], stripos($coordinates[0], ':') +1));

Assuming that the string always contains a colon.

Or if the identifier before the colon only contains characters (not numbers) you can do also this:

$string = "iPhone: 52.973053,-0.021447";
$string  = trim($string, "a..zA..Z: ");
//$string = "52.973053,-0.021447"

$coordinates = explode(',', $string);

Answer 3

Try:

$string = "iPhone: 52.973053,-0.021447";

preg_match_all( "/-?\d+\.\d+/", $string, $result );
print_r( $result );

Answer 4

I like @Felix's non-regex solution, I think his solution for the problem is more clear and readable than using a regex.

Don't forget that you can use constants/variables to change the splitting by comma or colon if the original string format is changed.

Something like

define('COORDINATE_SEPARATOR',',');
define('DEVICE_AND_COORDINATES_SEPARATOR',':');

Answer 5

$str="iPhone: 52.973053,-0.021447";
$s = array_filter(preg_split("/[a-zA-Z:,]/",$str) );
print_r($s);

Answer 6

An even more simple solution is to use preg_split() with a much more simple regex, e.g.

$str   = 'iPhone: 52.973053,-0.021447';
$parts = preg_split('/[ ,]/', $str);
print_r($parts);

which will give you

Array 
(
    [0] => iPhone:
    [1] => 52.973053
    [2] => -0.021447
)