PHP Find all occurrences of a substring in a string

Question

I need to parse an HTML document and to find all occurrences of string asdf in it.

I currently have the HTML loaded into a string variable. I would just like the character position so I can loop through the list to return some data after the string.

The strpos function only returns the first occurrence. How about returning all of them?

Answer 1

Without using regex, something like this should work for returning the string positions:

$html = "dddasdfdddasdffff"; $needle = "asdf"; $lastPos = 0; $positions = array();  while (($lastPos = strpos($html, $needle, $lastPos))!== false) {     $positions[] = $lastPos;     $lastPos = $lastPos + strlen($needle); }  // Displays 3 and 10 foreach ($positions as $value) {     echo $value ."<br />"; } 

Answer 2

You can call the strpos function repeatedly until a match is not found. You must specify the offset parameter.

Note: in the following example, the search continues from the next character instead of from the end of previous match. According to this function, aaaa contains three occurrences of the substring aa, not two.

function strpos_all($haystack, $needle) {     $offset = 0;     $allpos = array();     while (($pos = strpos($haystack, $needle, $offset)) !== FALSE) {         $offset   = $pos + 1;         $allpos[] = $pos;     }     return $allpos; } print_r(strpos_all("aaa bbb aaa bbb aaa bbb", "aa")); 

Output:

Array (     [0] => 0     [1] => 1     [2] => 8     [3] => 9     [4] => 16     [5] => 17 )