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
6 Answers
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
2 Comments
James Morris
I'm wondering if it's really necessary to match digits? Might be far simpler to split at colon and comma? (pls excuse me if this is dumb ;-)
Bart Kiers
That is an option if the string will always look like that. But perhaps the input changes slightly or the matching is also used for validation.
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);
Comments
Try:
$string = "iPhone: 52.973053,-0.021447";
preg_match_all( "/-?\d+\.\d+/", $string, $result );
print_r( $result );
Comments
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',':');
Comments
$str="iPhone: 52.973053,-0.021447";
$s = array_filter(preg_split("/[a-zA-Z:,]/",$str) );
print_r($s);
Comments
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
)
Comments
