How to add additional parameters to usort/uasort cmp function?

Question

I would like to have this $sort_flags array available within the compare_by_flags function, but I didn't find a way to this, is it possible?

public function sort_by_rank(array $sort_flags = array()) {
    uasort($this->search_result_array, array($this, 'compare_by_flags'));
}

private static function compare_by_flags($a, $b) {
    // I want to have this $sort_flags array here to compare according to those flags      
}

score 7 · Accepted Answer · answered Sep 12 '11 at 12:10

If you use php < 5.3 then you can just use instance variables:

public function sort_by_rank(array $sort_flags = array()) {
    $this->sort_flags = $sort_flags;
    uasort($this->search_result_array, array($this, 'compare_by_flags'));
}

private static function compare_by_flags($a, $b) {
    // I want to have this $sort_flags array here to compare according to those flags      
}

otherwise - use closures:

public function sort_by_rank(array $sort_flags = array()) {
    uasort($this->search_result_array, function($a, $b) use ($sort_flags) {
        // your comparison
    });
}

thanks, using the first approach and will switch as soon we upgrade php — Riesling, Sep 12 '11 at 16:07

score 2 · Answer 2 · edited May 23 '17 at 12:30

2

You don't mention what you want to achieve by passing the $sort_flags variable, but you might find this answer of mine useful (either as it stands, or as an example if you want to achieve something different).

edited May 23 '17 at 12:30

Community

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answered Sep 12 '11 at 12:12

Jon

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score -1 · Answer 3 · answered Sep 12 '11 at 12:09

You could set it as class static property, like this:

public function sort_by_rank(array $sort_flags = array()) {
    self::$_sort_flags = $sort_flags;
    uasort($this->search_result_array, array($this, 'compare_by_flags'));
}

private static function compare_by_flags($a, $b) {
    // Read self::$_sort_flags
    // I want to have this $sort_flags array here to compare according to those flags      
}

Also you could try this, as of PHP 5.3

uasort($array, function($a, $b) {
  self::compare_by_flags($a, $b, $sort_flags);
});

This exact code will not work, as long as anonymous function variable scope has no idea what `$sort_flags` is. — zerkms, Sep 12 '11 at 12:13

How to add additional parameters to usort/uasort cmp function?

3 Answers3