How to get count of substring in string using regular expressions?

Question

I have a string and format of substring, for example "Hello world!%1, abcdef%2, gfgf%14", i.e. format of substring is '%'+digit (0...infinity), and I need to get count of this substring in any string. I know about substring_count function, but for this function I need to know a defined line. So, please, tell me, how can I get count using regular expressions or anything else?

EDITED:

THis code works:

$r = "Hello world!%1, abcdef%2, gfgf%14";

$matches = array();
preg_match_all('/\%\d+/', $r, $matches);
echo isset($matches[0]) ? count($matches[0]) : 0;

But if I have a space before %1 or after it, the code doesn't work. Please, fix this expression. Thanks in advance.

What do you mean by "defined line"? Is your input string multiline, and yo want to know the line number of every matched occurance? — complex857
– complex857, Commented Jul 20, 2012 at 13:25
I mean that for substring_count() I must input "%1" or anything else for searching, but I know only format - "%"+digits. — user1538002
– user1538002, Commented Jul 20, 2012 at 13:28

Madara's Ghost · Accepted Answer · 2012-07-20 13:40:07Z

2

<?php

$str = "Hello world!%1, abcdef%2, gfgf%14";

$match_count = preg_match_all("/%\d+/", $str);

echo $match_count;

By the way, $matches will hold all of the matched substrings.

edited Jul 20, 2012 at 13:40

answered Jul 20, 2012 at 13:28

Madara's Ghost

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Miroshko · Accepted Answer · 2012-07-20 13:30:06Z

0

Use preg_match_all with $matches array (third parameter) and then calculate length or array of occurences:

$r = "Hello world!%1, abcdef%2, gfgf%14";

$matches = array();
preg_match_all('/\%\d+/', $r, $matches);
echo isset($matches[0]) ? count($matches[0]) : 0;

answered Jul 20, 2012 at 13:30

Miroshko

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3 Comments

user1538002 Over a year ago

One thing, please - modify your expression for spaces for left and right, for example "give me %1 and %2"

Miroshko Over a year ago

do you mean spaces must be present on both sides or may be present? current script says that "give me %1 and %2" has 2 occurences.

mcrumley Over a year ago

@Truth has the correct code. You don't need to count the results because preg_match_all returns the number of matches.

Pitchinnate · Accepted Answer · 2012-07-20 13:27:06Z

0

If you will never you use the % sign for anything other than defining a substring in my mind the easiest way is to do this:

$pieces = explode('%',$string);
$num_substrings = count($pieces) + 1;

answered Jul 20, 2012 at 13:27

Pitchinnate

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Comments

mcrumley · Accepted Answer · 2012-07-20 14:57:56Z

0

preg_match_all returns the number of matches.

$r = "Hello world!%1, abcdef%2, gfgf%14";
echo preg_match_all('/\%\d+/', $r, $matches);
// in PHP >= 5.4 you can leave out $matches

Result:

answered Jul 20, 2012 at 14:57

mcrumley

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