在具有多个结果的数组中查找匹配或最接近的值 php

Question

I am trying to figure out a way to get a matching or closest value in an array in php with multiple results.

Let's say I have an array like this:

$arr = [0, 2, 4, 6, 8, 10, 13, 100];

And I want to get the closest value to 3. This should output 2 and 4 since they are equally close.

I used some codeblock from another answer but this one only outputs one final value; 2 in this example.

function getClosest($search, $arr) {
    $closest = null;
    foreach ($arr as $item) {
        if ($closest === null || abs($search - $closest) > abs($item - $search)) {
            $closest = $item;
        }
    }
    return $closest;
}

How could I create a function that could help me achieve my goal?

Thank you.

Answer 1

As you may return several numbers, your result variable must be an array (with potentially only one value in it).

Then, you simply need to add a branch to detect an equality:

function getClosest($search, $arr) {
    $closest = array();
    foreach ($arr as $item) {
        if (count($closest) == 0 || abs($search - $closest[0]) > abs($item - $search)) {
            $closest = array(); // new minimal difference, reset array
            $closest[] = $item ; // add new best candidate as first item of the list
        }
        elseif(abs($search - $closest[0]) == abs($item - $search))
        {
            // same difference, add item to closest list
            $closest[] = $item ;
        }
    }
    return $closest;
}