preg_split in php to split string at the point which is preceded by digit and is followed by letters or blank space

Question

In order to split my string at the point which is preceded by digit and is followed by letters as:

 $str = '12jan';

I have used

$arr = preg_split('/(?<=[0-9])(?=[a-z]+)/i',$str);

It works file and gives the desired output. I want to update it so that it gives the same output for strings like.

$str='12 jan';
$str='12    jan';
$str='12/jan';
$str='12//jan';
$str='12/jan';
$str='12*/jan';
$str='12*//jan';

The code should work for any strings given above so that at the end of the day I have a array like

Array
(
    [0] => 12
    [1] => jan
)

Any help will be appreciated.

you have to create a separate ` preg_split` for each desired string — , Feb 27 '18 at 12:41
@Rekha are these values part of a larger string or is this the entire input string? Please clarify how `$str` can vary. — mickmackusa, Feb 27 '18 at 12:42

mickmackusa · Accepted Answer · 2018-02-28T05:46:30.330

This may be optimized if you answer my question in the comment.

Pattern: ~(?<=[0-9])[*/ ]*(?=[a-z]+)~i

Demo

The above will match zero or more *, / and/or space characters.

On your input strings, this will be just as accurate and faster:

Pattern: ~\d+\K[^a-z]*~i
or: ~\d+\K[*/ ]*~ (no case-sensitive pattern modifier is necessary)

Demo

The above will match zero or more non-alphabetical characters immediately following the leading digit(s).

And of course preg_split's cousins can also do nicely:

Here is a battery of PHP Demos.

$strings=['12jan','12 jan','12    jan','12/jan','12//jan','12/jan','12*/jan','12*//jan'];

foreach($strings as $string){
    var_export(preg_split('~(?<=[0-9])[*/ ]*(?=[a-z]+)~i',$string));
    echo "\n";
    var_export(preg_split('~\d+\K[*/ ]*~',$string));
    echo "\n";
    var_export(preg_match('~(\d+)[/* ]*([a-z]+)~i',$string,$out)?array_slice($out,1):'fail');
    echo "\n";
    var_export(preg_match('~(\d+)[/* ]*(.+)~',$string,$out)?array_slice($out,1):'fail');
    echo "\n";
    var_export(preg_match_all('~\d+|[a-z]+~i',$string,$out)?$out[0]:'fail');
    echo "\n---\n";
}

All methods provide the same output.

I always endeavor (and advise others) to avoid/minimize the use of capture groups, lookarounds, alternatives, and lazy quantifiers in an effort to improve performance. — mickmackusa, Feb 27 '18 at 14:05

Mukesh · Answer 2 · 2018-02-28T04:49:04.080

0

I have updated your code with preg_match Its gives output what exactly your needs

$str='12/jan';
preg_match('/^(\d*)[\*\s\/]*([a-z]{3})$/i', $str, $match);
print_r($match);

but the output is changed a little bit, It will be like below

array(
  0 => '12/jan', 
  1 => '12', 
  2 => 'jan'
)

edited Feb 28 '18 at 04:49

answered Feb 27 '18 at 13:13

Mukesh

150
1
10

1

This answer is unnecessarily complex, offers no explanation and features unnecessary escaping. – mickmackusa Feb 27 '18 at 13:50
This Maybe complex, But it gives the output as he wants – Mukesh Feb 28 '18 at 04:51

score 0 · Answer 3 · answered Feb 27 '18 at 13:20

A simple preg_match regexp does it:

foreach (['12 jan', '12    jan', '12/jan', '12//jan', '12/jan',
          '12*/jan', '12*//jan'] as $test)
{
        unset ($matches);
        if (preg_match("#^([0-9]+)[ /*]*(.*)#", $test, $matches)) {
                var_export( [$matches[1], $matches[2]] );
        }
        else {
                print "Failed for '$test'.\n";
        }
}

The regexp is:

start with numbers -> group #1
have 0 or more of space, slash or stars
take all the rest -> group #2

preg_split in php to split string at the point which is preceded by digit and is followed by letters or blank space

3 Answers3