Why below function returning me null instead of 1?

Question

I have written below function to process an array but It is not returning me 1 thought It's output $input[0] returning me 1. don't understand why It is return NULL. Anything I return in that condition is return me NULL. Please explain me if anyone know. Thanks.

function endWithNumber($input)
{
    if (count(array_unique($input)) === 1) {        
        return $input[0];       
    }
    $maxVal = max($input);
    $maxKey = array_search($maxVal,$input);

    foreach ($input as $k => $v) {
        if ($maxKey != $k && $maxVal != $v) {
            $newVal  = ($maxVal - $v);
            $input[$maxKey] = $newVal;
            break;
        }
    }

    endWithNumber($input);
}

$input = array(6,10,15);  
var_dump(endWithNumber($input));
exit;

change `endWithNumber($input);` to `return endWithNumber($input);` — Yoshi, Jun 04 '13 at 10:39
What is this code supposed to accomplish exactly? I'm sure there are much more elegant solutions to this. — deceze, Jun 04 '13 at 10:40
@Yoshi, Thanks Yoshi!! You're right.. but can you tell me why it is working like that? — Jimit, Jun 04 '13 at 10:41
@Jimit The code says *"if [condition], `return` something, else never return anything"*. It doesn't matter that the function calls itself recursively, that logic is the same for all code. — deceze, Jun 04 '13 at 10:43
@Yoshi, I have already return values in condition if satisfied... — Jimit, Jun 04 '13 at 10:46

zkanoca · Accepted Answer · 2013-06-04T10:49:15.327

Your function returns nothing until your array count is 1. Because your return statement is in if block.

<?php
function endWithNumber($input)
{
    if (count(array_unique($input)) == 1) 
        return $input[0];       

    $maxVal = max($input);
    $maxKey = array_search($maxVal,$input);

    foreach ($input as $k => $v) 
    {
        if ($maxKey != $k && $maxVal != $v) 
        {
            $newVal  = ($maxVal - $v);
            $input[$maxKey] = $newVal;
            break;
        }
    }   

    return endWithNumber($input);
}

$input = array(6,10,15);  
var_dump(endWithNumber($input));

exit;   
?>

Why below function returning me null instead of 1?

1 Answers1

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