How to build this kind of Logic using arrays in PHP - php

Question

I have an array which consists of this set of items
array(3) {
[0]=>
array(4) {
["Field1"]=>
string(8) "80000007"
["Field2"]=>
string(16) "O70000006"
["Field3"]=>
string(0) ""
["Field4"]=>12345
string(0) ""
}
[1]=>
array(4) {
["Field1"]=>
string(8) "80000008"
["Field2"]=>
string(16) "O70000007"
["Field3"]=>
string(0) ""
["Field4"]=>78965
string(0) ""
}
[2]=>
array(4) {
["Field1"]=>
string(8) "80000009"
["Field2"]=>
string(16) "H80000006"
["Field3"]=>
string(0) ""
["Field4"]=>12345
string(0) ""
}
}
Now my question is Iam trying to display only the items once from array or trying to filter the array in such a way if the "Field2" has
a value starting with "O" or "H" and their "Field4 " value should be different . If the "Field4" value is same for the each of the row
then we dont display that row or array item . For eaxample from the above array we will get 2 items as follows
1)80000007 O70000006 12345
2)80000008 O70000007 78965
//we are not displaying the 3rd Item
because The "Field4 " is same . we
display only once
foreach ($resultset as $key => $value){
echo $key."<br>"; /// outputs 0,1,2
echo $value['Field2']."<br>"; // outputs O70000006, O70000007, H80000006
}

Answer 1

function getField2_removeDupeField4($arr){
$f4 = array();
$f2 = array();
foreach($arr as $array){
if(in_array($array['Feild4'], $f4){ continue; }
$firstChar = substr($array['Feild2'], 0, 1);
if($firstChar == 'O' || $firstChar == 'H'){
$f2[] = $array;
$f4[] = $array['Feild4'];
}
}
return $f2;
}
So to get the array you want:
$new_arr = getField2_removeDupeField4($orig_arr);

Answer 2

So... you just want some way to skip rows whose Field4 has already been printed?
Set up an array to hold all the previously printed Field4s, and check against that before printing anything. Something like this:
$field4s = array();
foreach ($resultset as $key => $value){
$field4 = $value['Field4'];
if (($field4[0] == 'O' || $field4[0]=='H') && !in_array($field4 , $field4s) {
array_push($field4s, $field4);
echo $field4;
}
}