PHP: Sort array by value length

Looks like others have already answered but I started writing this so I'm going to post it, dang it! :)

You could take a look at usort

$data = ["this", "is", "a", "bunch", "of", "words"];

usort($data, function($a, $b) {
    $difference =  strlen($a) - strlen($b);

    return $difference ?: strcmp($a, $b);
});

I'm using the Elvis operator ?: to just return the difference based on the string lengths if it's not 0. If it is 0, just return the return value of strcmp

You can use a custom sort function for this.

function mycmp($a, $b) {
    $cmp = strlen($a) - strlen($b);
    if ($cmp === 0)
        $cmp = strcmp($a, $b);
    return $cmp;
}

usort($array, 'mycmp');

See this:

$myarray = explode(" ", "this is a bunch of words");
usort($myarray, function($a, $b) { return strlen($a) - strlen($b) });
print_r($array);

Explanation: usort sorts in place (i.e. by reference) an array, given a custom comparator. A comparator must return a negative number if the first item should be before the second item, and a positive otherwise. A value of 0 means they are equal regarding the order.

You can add custom criteria, not related to strlen() when the lengths are the same. That's up to you and involves just an additional if block.

It is important to note that the function must define an order relationship, as in math:

1. criteria(a, b)>0 and criteria(b, c)>0 implies criteria(a, c)>0.
2. the same applies to the lower-than sign, lower-than-or-equal, greater-than-or-equal, and equal.
3. criteria(a, b) should have an opposite sign of criteria(b, a).

Another method:

$f = fn($s1, $s2) => strlen($s1) <=> strlen($s2);
usort($a, $f);

https://php.net/language.operators.comparison