PHP Regex statements - php

Question

With a post request, I'm trying to return a booking number to my iOS App. It posts the current date as a string which is written to a file on my server.
The logic is, that whenever the date from the last entry does not match the date passed in the post request, the booking number starts from 01. If it is the same date, the booking number gets increased by one.
The text file I write my entries to looks like this:
2017-03-03, 1;
2017-03-03, 2;
2017-03-03, 3;
2017-03-03, 4;
2017-03-03, 5
I am using regex to find the last entry, comparing its date to the current and assigning the new booking number.
Here is my code:
if (preg_match_all("/\d{4}-\d{1,2}-\d{1,2},\s\d\z/", $textFileString, $entryArray)) {
if (preg_match_all("/\d{4}-\d{1,2}-\d{1,2}/", $entryArray[0][0], $dateArray)) {
if ($dateArray[0][0] == $currentDate) { //$currentDate's value comes from the post request
if (preg_match_all("/\d\z/", $entry[0][0], $numberArray)) {
$bookingNumber = $output_array[0][0]+1;
}
} else {
$bookingNumber = 1;
}
}
}
Note: I do successfully write to the file.

Answer 1

I suggest switching to preg_match (since you only need to find a single match) and add capturing groups to the pattern so as to reduce the code a bit:
$textFileString = '2017-03-03, 1;
2017-03-03, 2;
2017-03-03, 3;
2017-03-03, 4;
2017-03-03, 5';
$currentDate = '2017-03-03';
if (preg_match("/(\d{4}-\d{1,2}-\d{1,2}),\s(\d{1,2})\z/", $textFileString, $entryArray)) {
if ($entryArray[1] == $currentDate) { //$currentDate's value comes from the post request
$bookingNumber = $entryArray[2]+1;
} else {
$bookingNumber = 1;
}
}
echo $bookingNumber;
See the PHP demo.
Note you may also replace \z with $ since the $ anchor matches at the end of the string (or before a final LF in the string) by default.
Now, (\d{4}-\d{1,2}-\d{1,2}),\s(\d{1,2})\z contains two capturing groups that you may access via $entryArray[1] and $entryArray[2].