How Do I Implement Incomplete Answer to Old Question - php

Question

This comment looks like it would work if the author included the value for $numbers. They say it is some type of array, but don't provide enough information to replicate it. I picture some hard coded array ranging from 0 to 9, but I can't help think that such an array would miss numbers greater than 9. What does the numbers array in this example look like?
$text = "1 out of 23";
if(preg_match_all('/\d+/', $text, $numbers))
$lastnum = end($numbers[0]);
I would just post a comment asking whoever wrote that to paste the value for $numbers, but it says I need reputation points to do that.
See How do I grab last number in a string in PHP?

Answer 1

To answer your initial question print_r() can be used to output all contents of an array. e.g. print_r($numbers)
https://3v4l.org/2jA1b
To explain the code:
\d is a single number
+ is a quantifier meaning one or more of the previous character or group
so this would find all numbers in a string. The $numbers[0] would be all numbers, 1 per index, and the end() pulls to the last number/index. Each index would be a number, the 0 is all matches, each indice at the root level is a capture group.
This code wouldn't work as intended for decimals or comma delimited integers. In those cases the numbers would be split up at the delimiter. 1.0 would become 1 and 0 (2 different numbers).
You could rewrite this as:
$text = "1 out of 23";
if(preg_match('/.*\K\D\d+/', $text, $numbers))
echo $numbers[0];
so the end function is not needed. This pulls everything until the last number then forgets everything before the last number.

Answer 2

What you are trying to do is likely easier using preg_split instead of preg_match_all. We can split the input text by the matched regex (digits) and then rebuild the string while incrementing the numbers as we go.
<?php
function incrementNumbers($text) {
// NOTES:
// parenthesis are important in the regex in order to return the captured values
// the -? will capture negative numbers too if necessary
// PREG_SPLIT_DELIM_CAPTURE allows the captured values to be returned too
$split = preg_split('/(-?\d+)/', $text, -1, PREG_SPLIT_DELIM_CAPTURE);
$return = '';
foreach($split as $i => $s) {
// because we didn't use PREG_SPLIT_NO_EMPTY, $split[0] will either be an empty string if
// $text began with a number, or the text before the first number. Either way, $split alternates
// between non-number [0], number [1], non-number [2], number [3], etc which is why we can detect
// even or odd indexes to determine if this is a number that needs to be incremented or not
if ($i % 2 === 0) {
$return .= $s;
} else {
$return .= (intval($s) + 1);
}
}
return $return;
}
Examples:
echo incrementNumbers("1 out of 23 with 1 and 1 and 24 and 23");
echo incrementNumbers("1 1 2 2 3 3 2 2 1 1");
echo incrementNumbers("0 1 2 3 4 5 6 7");
echo incrementNumbers("-3 -2 -1 0 1 2 3 4 5 6 7");
echo incrementNumbers("there are no numbers in this text");
echo incrementNumbers("does not start 999 with a number 123 nor end 17 with a number");
Outputs:
2 out of 24 with 2 and 2 and 25 and 24
2 2 3 3 4 4 3 3 2 2
1 2 3 4 5 6 7 8
-2 -1 0 1 2 3 4 5 6 7 8
there are no numbers in this text
does not start 1000 with a number 124 nor end 18 with a number
Working example at https://3v4l.org/iKskO