PHP Sort array joint positions - php

Question

I have an array of players each with a number of points.
I can easily sort the array in order of the points using a custom usort function.
But when two players have the same amount of points I need to rank them as the same winning position within the list.
E.g.
Nick - 25
Tom - 18
Chris - 18
Dave - 16
James - 8
In this case the data that I require would be
Nick - 1st
Tom - (joint) 2nd
Chris - (joint) 2nd
Dave 3rd
James 4th
So players with equal scores are designated the same ranking position.
What is the best way of calculating these positions?
Thanks!

Answer 1

This will give you what you want with an additional fix: if you have two players in position 2 the next player should be in position 4. If you don't want this additional fix move $count++; into the if statement.
$count = 0;
$position = 0;
$last_score = -1;
foreach ($players as $player)
{
$count++;
if ($last_score !== $player->score)
{
$position = $count;
}
$player->position = $position;
$last_score = $player->score;
}

Answer 2

I think the following code would do the job as required:
$scores = array('Nick'=>25,'Tom'=>18,'Chris'=>18,'Dave'=>16, 'James'=> 8,);
$scores_numbers = array_unique(array_values($scores));
$scores_counter = array_count_values($scores);
$pos = 1;
foreach($scores_numbers as $num) {
foreach($scores as $name=>$score) {
if($num == $score) {
if($scores_counter[$score] > 1) {
echo "$name - (joint) $pos<br />";
} else {
echo "$name - $pos<br />";
}
}
}
$pos++;
}
I have updated the code to avoid the duplicating output.

Answer 3

If you are retrieving player stats from DB then below code can be useful to rank them :
<?php
$players = [
['name' => 'Ash',
'point' => 0
],
['name' => 'Bob',
'point' => 10
],
['name' => 'Cane',
'point' => 0
],
['name' => 'Dory',
'point' => 6
],
['name' => 'Efat',
'point' => 6
],
];
usort($players, function($v1, $v2){
return $v2['point'] - $v1['point'];
});
$ranking = [];
$currentPosition = 0;
$heighestPoint = PHP_INT_MIN;
foreach($players as $player){
if($heighestPoint !== $player['point']){
$currentPosition++;
$heighestPoint = $player['point'];
}
$ranking[$currentPosition][] = $player;
}
print_r($ranking);
Output :
Array
(
[1] => Array
(
[0] => Array
(
[name] => Bob
[point] => 10
)
)
[2] => Array
(
[0] => Array
(
[name] => Dory
[point] => 6
)
[1] => Array
(
[name] => Efat
[point] => 6
)
)
[3] => Array
(
[0] => Array
(
[name] => Ash
[point] => 0
)
[1] => Array
(
[name] => Cane
[point] => 0
)
)
)

Answer 4

May it helps
/*Below array must be sorted */
$a1=array("Nick"=>25,"Tom"=>18,"Chris"=>18,"Dave"=>16,"James"=>8);
$makeUnique=array_unique($a1);
$makeUnique=array_values($makeUnique);
$pArr=array_map('setPosition',$a1);
print_r($pArr);
function setPosition($a){
Global $makeUnique;
return array_search($a,$makeUnique)+1;
}
OUT PUT
Array ( [Nick] => 1 [Tom] => 2 [Chris] => 2 [Dave] => 3 [James] => 4 )

Answer 5

I used usort to sort assoc array
$players = [["name" => "Nick" , "score" => 25] , ["name" => "Tom" , "score" => 18] , ["name" => "chris" , "score" => 18] , ["name" => "dave" , "score" => 16 ] , ["name" => "james" , "score" => 8]];
usort($players , function($a , $b) {return $b["score"] - $a["score"];} );
var_dump($players);
$lastScore = null;
$pos = 1;
foreach($players as $player)
{
if($lastScore != null && $lastScore == $player["score"])
echo $pos-1 . " - " . $player["name"] . '<br/>';
else
echo $pos++ . " - " . $player["name"] . '<br/>';
$lastScore = $player["score"];
}
checkout this code in teh playground