Use array_count_values() and still keep key -- PHP

Question

Let's say I have two arrays...

$radicand_array = array(3, 5, 5, 2);
$coeff_array = array(-10, 14, 3, -6);

I'd like to be able to determine which (if any) values in $radicand_array match, AND also know what the keys are. So, in this case I would want to know that there's a match on keys 1 and 2 of $radicand_array.

I need to know this because I want to then add the corresponding key values in $coeff_array. So, in this case I would then add 14 and 3 based on the matching 5's in $radicand_array.

I've tried array_count_values(), but it doesn't seem to give the key values like I want. Is there a PHP function ready made for this?

Here appears a promising answer: stackoverflow.com/questions/6460993/… — Vladimir Ramik
– Vladimir Ramik, Commented Mar 10, 2015 at 2:17
As explained in the post, I would expect the output to tell me that keys 1 and 2 match in $radicand_array. If $radicand_array was array(3, 5, 5, 2, 5), then I would expect the output to tell me that keys 1, 2, and 4 match. — gtilflm
– gtilflm, Commented Mar 10, 2015 at 2:44

Vladimir Ramik · Accepted Answer · 2015-03-10 03:09:30Z

0

Using the link:

Fixed. Good man!

<?php
    // $radicand_array = array(3, 5, 5, 2);
    $radicand_array = array(3, 5, 5, 2, 3, 3);
    $coeff_array = array(-10, 14, 3, -6);

    $unique = array_unique($radicand_array);
    $duplicates = array_diff_assoc($radicand_array, $unique);

    // Duplicate keys
    $aDupes = array_keys(array_intersect($radicand_array, $duplicates));
    $iSum = 0;
    $iCountDupes = count( $aDupes );
    for( $i = 0; $i < $iCountDupes; ++$i )
    {
        if( !empty( $coeff_array[ $aDupes[ $i ] ] ) )
        {
            $iSum = $iSum + $coeff_array[ $aDupes[ $i ] ];
        }
    }
    var_dump( $iSum );
?>

edited Mar 10, 2015 at 3:09

answered Mar 10, 2015 at 2:45

Vladimir Ramik

1,9302 gold badges14 silver badges23 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Kevin Over a year ago

almost there, use those keys in the second array and get the sum

gtilflm Over a year ago

I just found an issue. This seems to not work if $radicand_array were like this: $radicand_array = array(3, 5, 5, 2, 3, 3);. In other words, if there are multiple matches. Does that completely change things?

Vladimir Ramik Over a year ago

Fixed. Needs an empty check if the coeff array has less values.

gtilflm Over a year ago

I should have been more specific. I'm assuming that $coeff_array has a matching number of values. I believe I've got it though, so I'll be posting that as an answer in a moment. Credit to Vladimir Ramik though.

gtilflm · Accepted Answer · 2015-03-10 03:19:53Z

This is an edited version of Vladimir Ramik's post to handle multiple sets of matches...

$radicand_array = array(3, 5, 5, 2, 3);
$coeff_array = array(-10, 14, 3, -6, 4);

$unique = array_unique($radicand_array);
$duplicates = array_diff_assoc($radicand_array, $unique);

$new_array = array_chunk($duplicates, 1);
// Duplicate keys
$aDupes = array_keys(array_intersect($radicand_array, $new_array[0]));

$iCountDupes = count( $aDupes );
        for($i = 0; $i < $iCountDupes; ++$i){
            $ans_coeff_1 += $coeff_array[$aDupes[ $i ]];
        }

        echo $ans_coeff_1;

// Duplicate keys
$bDupes = array_keys(array_intersect($radicand_array, $new_array[1]));

$iCountDupes = count( $bDupes );
        for($i = 0; $i < $iCountDupes; ++$i){
            $ans_coeff_2 += $coeff_array[$bDupes[ $i ]];
        }

        echo '<br>' . $ans_coeff_2;

Collectives™ on Stack Overflow

Use array_count_values() and still keep key -- PHP

2 Answers 2

4 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

4 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related