Re: [discussion] add array_usearch()

Hi Chris, On Fri, Feb 7, 2014 at 4:28 AM, Chris Wright <daverandom@php.net> wrote: > On 6 February 2014 19:55, Tjerk Meesters <tjerk.meesters@gmail.com> wrote: > > Consider the following examples for finding a value in an array: > > > > array_search($value, $array, true); > > > > current(array_keys($array, $value, true)); > > > > key(array_filter($array, function($item) use ($value) { > > return $item === $value; > > })); > > > > Perhaps I've overlooked one way, but that's already three ways of doing > > something similar; the difference lies in the memory behaviour, the first > > being O(1) whereas the other two are O(n). > > I'm not sure where you got this statement from. array_search() is > still O(n) in the worst case (when the needle is not found), which is > the best you can hope for with such an operation. It's true that the > other two are *always* O(n) whereas array_search() *could* return > sooner than a complete iteration if the needle is found before the > last element. > I was talking about memory growth, not runtime :) > > My initial reaction to this is one of "ye gods, not another array_* > function", but I wouldn't be against altering the existing > array_search() so that the third parameter is a bitmask of flags, one > of which could indicate that the search should be case insensitive. > This could be done in a BC-compliant manner if the flag that indicates > strict comparisons has a value of 1. > I'm not wildly enthusiastic about another magic flags parameter, but it's an acceptable compromise for me. The slight advantage there is that in_array() would be bestowed upon the ability to take a callback function as well. Something like: if (in_array('is_numeric', $array, SEARCH_NEEDLE_IS_CALLBACK)) { ... } > > Thanks, Chris > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: http://www.php.net/unsub.php > > -- -- Tjerk