PHP compare values in a single array and output the difference - php

Question

I have an array that looks like this:
$rowarray(
[0] => [PID] => 97162 [TID] => 340 [StatsID] => 49678
[1] => [PID] => 97165 [TID] => 340 [StatsID] => 49673
[2] => [PID] => 97167 [TID] => 340 [StatsID] => 49675
[3] => [PID] => 97162 [TID] => 340 [StatsID] => 49679
)
Then my code looks like this:
$cntr=0;
foreach($rowarray as $row)
{
echo "<tr><td>$row[PID] $row[TID] $row[StatsID] </td></tr>";
$cntr++;
}
Two things I want to do I want to be able not print the duplicates in the array but print the additional column that has a different value. So my desired output would look like this.
97162 340 49678 49679
97165 340 49673
97167 340 49675
I started out with the array_unique() but that only returned:
97162 340 49678

Answer 1

Assuming only the StatsID changes (not clear from the question)
$map = array();
foreach($rowarray as $row){
$k = $row["PID"] . '-' . $row["TID"];
if( !isset( $map[$k] ) ){
$map[$k] = array();
}
array_push( $map[$k], $row["StatsId"] );
}
foreach($map as $k=>$v){
$row = explode( '-', $k );
echo "<tr><td>$row[0] $row[1] " . implode( " ", $v ) . " </td></tr>";
}

Answer 2

Here's what I'd do:
Start by sorting the array (using usort to sort by PID, then by TID)
Initialize "last" variables ($last_PID and $last_TID). They will store the respective values in the loop
In the loop, first compare the "current" variables to the "last" ones, if they're the same then just echo the StatsID value.
If they're not the same, output the <tr> (but not the final </tr>, so the first part of the loop can add more StatsID values if necessary)
Still inside the loop, after outputting everything, update the "last" variables.
After the loop, output the final </tr>
This may not be optimal, but I'm pretty sure it'll work.

Answer 3

Transfer the $rowarray structure into a map of maps of arrays, like this:
$rowarray = array(
array('PID' => 97162, 'TID' => 340, 'StatsID' => 49678),
array('PID' => 97165, 'TID' => 340, 'StatsID' => 49673),
array('PID' => 97167, 'TID' => 340, 'StatsID' => 49675),
array('PID' => 97162, 'TID' => 340, 'StatsID' => 49679)
);
$keys = array();
foreach ($rowarray as $row) {
if (!is_array(#$keys[$row['TID']])) {
$keys[$rowarray['TID']] = array();
}
if (!is_array(#$keys[$row['TID']][$row['PID']])) {
$keys[$row['TID']][$row['PID']] = array();
}
$keys[$row['TID']][$row['PID']][] = $row['StatsID'];
}
foreach ($keys as $pid => $pid_arr) {
foreach ($pid_arr as $tid => $tid_arr) {
echo "<tr><td>$tid $pid " . implode(' ', $tid_arr) . "</td></tr>";
}
}
See this code in action

Answer 4

As far as I can tell, the only way to do this would be to loop through the array creating a new unique array as you go.
$unique = array();
foreach ($row as $value)
{
$key = $value['PID'];
if (isset($unique[$key]))
{
$unique[$key]['StatsID'] .= ' ' . $value['StatsID'];
}
else
{
$unique[$key] = $value;
}
}
Now, $unique would give you the results you're looking for and you can loop through the unique array and output your results (I also added your counter if needed):
$count = count($unique);
foreach ($unique as $row)
{
echo "<tr><td>{$row['PID']} {$row['TID']} {$row['StatsID']} </td></tr>";
}