Best way around combine_array with identical keys? - php

Question

I was using combine_array to update a MySQL table from a CSV file. I thought everything was working like a champ, but it turns out the data source isn't amazing. There are multiple columns with the same name and those columns become the keys in an array. Example take the two arrays:
array 1
[0]=>"name"
[1]=>"email"
[2]=>"shoe size"
[3]=>"email"
array 2
[0]=>"Jake Doe"
[1]=>"jake#example.mail"
[2]=>"10.5"
[3]=>""
if I was to use array_combine($array1,$array2) I would get:
["name"]=>"Jake Doe"
["email"]=>""
["shoe size"]=>"10.5"
The problem is that I'd obviously prefer to have the email not get overwritten by a blank value. What I can up with is the function below. What I'm looking for is just a second set of eyes. Is this there a better way to do this? I hate that I have two nested ifs, but I'm not sure how I'd go about making it cleaner or if that's even possible.
//array_combine simply overwrites repeat keys, this only overwrites if the value is empty
//if the first instance of the key has a value, it ignores duplicate keys
function new_array_combine($key_array,$value_array){
foreach($value_array as $key=>$value){
if(array_key_exists($key_array[$key],$new_array)){
if(empty($new_array[$key_array[$key]]))$new_array[$key_array[$key]]=$value;
}else{
$new_array[$key_array[$key]]=$value;
}
}
return $new_array;
}

Answer 1

The only problem I see with your program is when key names do not match in each array
array 1
[0]=>"name"
[1]=>"email"
[2]=>"shoe size"
[3]=>"email"
array 2
[0]=>"Jake Doe"
[1]=>"jake#example.mail"
[3]=>"10.5"
[4]=>""
Suggested modifications:
function new_array_combine($a1, $a2){
$result=Array();
reset($a1);
foreach($a2 as &$v){
$key=current($a1);
if (!isset($result[$key])||empty($result[$key]))
$result[$key]=$v;
next($a1);
}
return $result;
}

Answer 2

Blah. Trying to rescue this response, since my first obviously missed the entire point of the post.
If you're only worried about those blank values, then I would say you could walk the arrays once through first, 'cleaning' them by deleting indexes with no corresponding value:
<?php
// $a and $b as defined in the example
foreach($a as $k => $v) {
if(empty($b[$k])) {
unset($a[$k]);
unset($b[$k]);
}
}
$c = array_combine($a, $b);
print_r($c);
Output:
Array(
[name] => Jake Doe
[email] => jake#example.mail
[shoesize] => 10.5
)
Edit: To include blank values (but still not let blanks override existing values), first get the unique keys from $a and use it to build an empty result array, then just skip blank values while looping through...
<?php
// $a and $b as defined in the example
$result = array();
$keys = array_unique($a);
foreach($keys as $key) $result[$key] = '';
foreach($a as $k => $v) {
if(empty($b[$k])) continue;
$result[$v] = $b[$k];
}
print_r($result);
Output:
Array(
[name] => Jake Doe
[email] => jake#example.mail
[shoesize] => 10.5
)