How to normalize string in PHP for desired output? - php

Question

Having some trouble normalizing some strings in PHP...
Given these test cases:
Van Fleur, Pat
Smith,John K
Smith, John Jr.
Smith,Jose Jr
I am attempting to normalize names in a list that use the format: Lastname,Firstname
Expected output for the test cases:
Van Fleur,Pat
Smith,John
Smith,John
Smith,Jose
I am using the following line, but appears I'm only getting a subset of these test cases accounted for.
Using this: strtok(trim(strtolower($name)), ' ')
I'm not great at regex, so really haven't ventured down that road yet.
Can you assist me with achieving the desired output using either regex or native functions?

Answer 1

No way around that, you need to somehow iterate over that data array and convert each entry:
<?php
$data = [
'Van Fleur, Pat',
'Smith,John K',
'Smith, John Jr.',
'Smith,Jose Jr'
];
array_walk($data, function($value, $key) use (&$data) {
preg_match('|\s*(\w.+),\s*(\w+)|', $value, $token);
$data[$key] = sprintf('%s,%s', $token[1], $token[2]);
});
print_r($data);
The output obviously is:
Array
(
[0] => Van Fleur,Pat
[1] => Smith,John
[2] => Smith,John
[3] => Smith,Jose
)
An obvious alternative is something like that:
<?php
$input = [
'Van Fleur, Pat',
'Smith,John K',
'Smith, John Jr.',
'Smith,Jose Jr'
];
$output = array_map(function($value) {
preg_match('|\s*(\w.+),\s*(\w+)|', $value, $token);
return sprintf('%s,%s', $token[1], $token[2]);
}, $input);
print_r($output);
But be careful here, such an approach won't scale well, since you actually double the memory footprint of the data that way...
So maybe that alternative would even be more elegant, since just as the first example it does an in-place change of the entries:
<?php
$data = [
'Van Fleur, Pat',
'Smith,John K',
'Smith, John Jr.',
'Smith,Jose Jr'
];
foreach($data as &$entry) {
preg_match('|\s*(\w.+),\s*(\w+)|', $entry, $token);
$entry = sprintf('%s,%s', $token[1], $token[2]);
}
print_r($data);
Considering your comment below which describes a slightly different scenario I would add this suggestion:
$entry = preg_replace('|^\s*(\w.+),\s*(\w+)\s*.*$|', '$1,$2', $entry);

Answer 2

Capture the leading substring until the ,, then match (but don't capture) the comma and optional space, then greedily capture non-space characters, then just match the rest of the string so that the replacement value overwrites the full original value.
Using negated character classes speeds up the pattern. Here is a simple one-call method:
Pattern Demo
Code: (Demo)
$names=[
'Van Fleur, Pat',
'Smith,John K',
'Smith, John Jr.',
'Smith,Jose Jr'
];
$names=preg_replace('/([^,]+), ?([^ ]+).*/','$1,$2',$names);
var_export($names);
Output:
array (
0 => 'Van Fleur,Pat',
1 => 'Smith,John',
2 => 'Smith,John',
3 => 'Smith,Jose',
)
Let's consider some more complex hypothetical inputs -- including names that don't need correcting.
Van Fleur, Pat // <-- 1 replacement
Smith,Josiah // <-- nothing to fix
Smith,John K // <-- 1 replacement
Smith,John Jacob Jingleheimer // <-- 1 long replacement
O'Shannahan-O'Neil, Sean Patrick Eamon // <-- double surname with apostrophes
de la Cruz, Bethania // <-- 3-word surname
Smith, John Jr. // <-- 2 replacements
Smith,Jose Jr // <-- 1 replacement
You can use my first posted pattern which is an efficient pattern, but it will execute replacements on names that do not require any fixes.
Alternatively, you can use this "capture-less" pattern: /,\K | [^,]*$/ with an empty replacement string. This will use many more steps, but will avoid performing needless replacing.
Code: (Demo)
$names=preg_replace('/,\K | [^,]*$/','',$names);
var_export($names);
Output:
array (
0 => 'Van Fleur,Pat',
1 => 'Smith,Josiah',
2 => 'Smith,John',
3 => 'Smith,John',
4 => 'O\'Shannahan-O\'Neil,Sean',
5 => 'de la Cruz,Bethania',
6 => 'Smith,John',
7 => 'Smith,Jose',
)
Lastly, if you have some deep-seated hate for regex (I certainly don't), you can use this method:
foreach($names as &$name){
$parts=explode(',',$name);
$name=$parts[0].','.explode(' ',ltrim($parts[1]),2)[0];
}
unset($name); // this is not required, but many recommend it to prevent issues downscript
var_export($names);
The decision about which one is best for your project, will come down to the quality of your real data and your personal tastes. I suggest running some comparative speed tests if optimization is a priority.

Answer 3

Try this:
^([^\,]+)\,\s?([^\s]+)