I am trying to grab text from a string that begins after the 3rd instance of a repeating variable
t|1t|2t|3t|4
I want to return the number 3 by finding the 3rd "t|"
I know how to get the string:
$pc1 = 'start';
$pc2 = 'end';
$pcb = strpos($string, $pc1,+2);
$pce = strpos($string, $pc2);
$data_point = substr($string,$pcb,$pce - $pcb);
But if I search for "t|" inside $data_point, it always leaves me with the first one and not the third
You can explode the string into an array and get the number:
$arr = explode('t|', $string)
print_r($arr);
output:
Array
(
[0] =>
[1] => 1
[2] => 2
[3] => 3
[4] => 4
)
To find the last occurance you need to use strrpos
$original = '7853412365412390';
$search = '123';
$position = strrpos($original, $search);
$position will be 11. With substr you get 5.
For more informations: https://www.php.net/manual/en/function.strrpos.php
You can also use explode, this give what is immediately after the end of the matched pattern.
function pattern_match($i = 0, $txt = "", $pattern = "")
{
$j = 0;
while($j <= strlen($txt)) {
if ($j >= strlen($pattern)) return true;
if ($pattern[$j] != $txt[$i + $j]) return false;
$j++;
}
}
function scan($txt = "", $pattern = "")
{
$i = 0; $matches = [];
while ($i <= strlen($txt)) {
if(pattern_match($i, $txt, $pattern)) $matches[] = $i + strlen($pattern) - 1;
$i++;
}
return $matches;
}
function get_nth($n = 0, $txt = "", $pattern = "", $j = 1)
{
$indicies = scan($txt, $pattern);
return $indicies[$n] ? substr($txt, $indicies[$n] + 1, $j) : null;
}
$txt = "t|1t|2t|3t|xyz012";
$pattern = "t|";
var_dump(
get_nth(0, $txt, $pattern),
get_nth(1, $txt, $pattern),
get_nth(2, $txt, $pattern),
get_nth(3, $txt, $pattern, 3) // any char to the right
)
// string(1) "1" string(1) "2" string(1) "3" string(3) "xyz"
