Unsetting arrays with a specific value in a multidimensional array? - php

Question

I am checking that certain elements in sub-arrays in a multidimensional array are not equal to a value and un-setting the array with that value from the multi array. I built a function so that I could easily implement this, however it doesn't appear to be working.
function multi_unset($array, $unset) {
foreach($array as $key=>$value) {
$arrayU = $array[$key];
$check = array();
for($i = 0; $i < count($unset); $i++) { // produces $array[$key][0, 2, 3]
array_push($check, $arrayU[$unset[$i]]);
}
if(in_array("-", $check)) {
unset($array[$key]);
}
}
return $array;
}
$arr = array(array("-", "test", "test", "test"), array("test", "test", "test", "test"));
$unset = array(0, 2, 3); // keys in individual arrays to check
multi_unset($arr, $unset);
print_r($arr); // Should output without $arr[0]
In this case, I'm checking if each sub-array has a "-" value in it and un-setting the array from the multi array. I am only checking specific keys in the sub-arrays (0, 2, 3) however it outputs an array without any changes. I figured I must have some scoping wrong and tried to use "global" everywhere possible, but that didn't seem to fix it.

Answer 1

Modified your version a bit and handled the return value.
function multi_unset($array, $unset)
{
$retVal = array();
foreach($array as $key => $value)
{
$remove = false;
foreach($unset as $checkKey)
{
if ($value[$checkKey] == "-")
$remove = true;
}
if (!$remove)
$retVal[] = $value;
}
return $retVal;
}
$arr = array(array("-", "test", "test", "test"), array("test", "test", "test", "test"));
$unset = array(0, 2, 3);
$arr = multi_unset($arr, $unset);
print_r($arr);

Answer 2

You may want to do some reading into Passing by Reference vs passing by value in PHP.
Heres some code that works with the given data set....
// Note the pass by reference.
function multi_unset(&$array, $unset) {
foreach($array as $pos => $subArray) {
foreach($unset as $index) {
$found = ("-" == $subArray[$index]);
if($found){
unset($subArray[$index]);
// Ver 2: remove sub array from main array; comment out previous line, and uncomment next line.
// unset($array[$pos]);
}
$array[$pos] = $subArray; // Ver 2: Comment this line out
}
}
//return $array; // No need to return since the array will be changed since we accepted a reference to it.
}
$arr = array(array("-", "test", "test", "test"), array("test", "test", "test", "test"));
$unset = array(0, 2, 3);
multi_unset($arr, $unset);
print_r($arr);