Get text contained within the parentheses at the end of string - php

Question

Say I have this user list:
Michael (43)
Peter (1) (143)
Peter (2) (144)
Daniel (12)
The number in the furthest right set of parentheses is the user number.
I want to loop each user and get the highest user number in the list, which in this case would be 144.
How do I do this? I'm sure it can be done with some kind of regexp, but I have no idea how. My loop is simple:
$currentUserNO = 0;
foreach ($users as $user) {
$userNO = $user->NameUserNo; // NameUserNo is the string to be stripped! ex: "Peter (2) (144)" => 144
if ($userNO > $currentUserNO) {
$currentUserNO = $userNO;
}
}
echo "The next user will be added with the user number: " . $currentUserNO + 1;

Answer 1

You could use a regex like:
/\((\d+)\)$/
^ glued to the end of the string
^^ closing parentheses
^^^ the number you want to capture
^^ opening parentheses
to capture the number in the last set of parentheses / at the end of the string.
But you could also use some basic array and string functions:
$parts = explode('(', trim($user->NameUserNo, ' )'));
$number = end($parts);
which breaks down to:
trim the closing parentheses and spaces from the end (strictly speaking from the beginning and end, you could also use rtrim());
explode on the opening parentheses;
get the last element of the resulting array.

Answer 2

If you are not confortable with regular expression you should not use them (and start to seriously learn them* as they are very powerful but cryptic).
In the mean time you don't have to use regex to solve your problem, just use (assuming that the NameUserNo contains just a line of the list) :
$userNO = substr(end(explode('(',$user->NameUserNo;)),0,-1);
It should be easier to understand.
* Is there a good, online, interactive regex tutorial?

Answer 3

I think the regular expression you are looking for is:
.+\((\d+)\)$
Which should select all characters until it reaches the last number wrapped in parenthesis.
The PHP code you can use to extract just the number is then:
$userNO = preg_replace('/.+\((\d+)\)$/', '$1', $user);
I haven't tested this, but it should set $userNO to 43 for the user Michael and 143 for the user Peter and so on.

Answer 4

I guess this is basically what you are looking for:
<?php
$list = array();
foreach $users as $user) {
preg_match('/$([a-zA-Z]+).*\([1-9]+\)$/', , $tokens);
$list[$tokens[2]] = $tokens[1];
}
ksort($list);
$highest = last(array_keys($list));
echo "The next user will be added with the user number: " . $highest++;

Answer 5

This is pretty easy to do with a regex.
foreach ($users as $user) {
# search for any characters then a number in brackets
# the match will be in $matches[1]
preg_match("/.+\((\d+)\)/", $user->NameUserNo, $matches);
$userNO = $matches[1];
if ($userNO > $currentUserNO) {
$currentUserNO = $userNO;
}
}
Because regexs use greedy matching, the .+, which means search for one or more characters, will grab up as much of the input string as it can before it reaches the number in brackets.

Answer 6

I'm fairly new to PHP, but couldn't you do it with:
$exploded = explode(" ", $user->NameUserNumber);
$userNo = substr(end($exploded), 1,-1);