Group array items by multiple values and sum the groups

Question

I have 2D array (showed bellow) - output of wp_query (Wordpress).

I need to group the arrays by index 0, 1, 2 values (lets think that the primary key is composed from these values and it should be unique in result table) and sum the index 3 values.

array(4) {
  [0]=>  string(6) "Team 1"
  [1]=>  string(6) "Jack"
  [2]=>  string(6) "Daniels"
  [3]=>  string(2) "10"
}
array(4) {
  [0]=>  string(6) "Team 1"
  [1]=>  string(3) "Jan"
  [2]=>  string(6) "Novak"
  [3]=>  string(2) "33"
}
array(4) {
  [0]=>  string(6) "Team 2"
  [1]=>  string(4) "John"
  [2]=>  string(3) "Doe"
  [3]=>  string(2) "11"
}
array(4) {
  [0]=>  string(6) "Team 2"
  [1]=>  string(4) "Jane"
  [2]=>  string(3) "Doe"
  [3]=>  string(2) "18"
}
array(4) {
  [0]=>  string(6) "Team 1"
  [1]=>  string(6) "Jack"
  [2]=>  string(6) "Daniels"
  [3]=>  string(1) "5"
}
array(4) {
  [0]=>  string(6) "Team 1"
  [1]=>  string(3) "Jan"
  [2]=>  string(6) "Novak"
  [3]=>  string(2) "33"
}
array(4) {
  [0]=>  string(6) "Team 2"
  [1]=>  string(4) "John"
  [2]=>  string(3) "Doe"
  [3]=>  string(2) "11"
}
array(4) {
  [0]=>  string(6) "Team 2"
  [1]=>  string(4) "Jane"
  [2]=>  string(3) "Doe"
  [3]=>  string(2) "18"
}

ETC...

Output should be someting like:

array(4) {
  [0]=>  string(6) "Team 1"
  [1]=>  string(6) "Jack"
  [2]=>  string(6) "Daniels"
  [3]=>  string(2) "15" (5+10)
}
array(4) {
  [0]=>  string(6) "Team 1"
  [1]=>  string(3) "Jan"
  [2]=>  string(6) "Novak"
  [3]=>  string(2) "66" (33+33)
}
array(4) {
  [0]=>  string(6) "Team 2"
  [1]=>  string(4) "John"
  [2]=>  string(3) "Doe"
  [3]=>  string(2) "22" (11+11)
}
array(4) {
  [0]=>  string(6) "Team 2"
  [1]=>  string(4) "Jane"
  [2]=>  string(3) "Doe"
  [3]=>  string(2) "36" (18+18)
}
}

I tried to do this by recursive for loops, but I cannot find the reason why is it not working properly.

$vysledna_tabulka = array();
$aktualni;

foreach($seznam_vsech_hracu_vsech_tymu as $radek){

    if(empty($vysledna_tabulka)){
        array_push($vysledna_tabulka,$radek);
    } else{
        foreach($vysledna_tabulka as $vysledny_radek){
            if($vysledny_radek[0]==$radek[0] && $vysledny_radek[1]==$radek[1] && $vysledny_radek[2]==$radek[2]){
                $vysledny_radek[3]+=$radek[3];
            } else {
                $aktualni = $radek; 
            }
        }    
        array_push($vysledna_tabulka,$aktualni);   
    }
}

I think there should be a better way to do this. Is there anyone who could help me?

Thanks.

Probably the best solution would be to change the query to do the grouping and summation for you — RiggsFolly, Sep 02 '21 at 17:17

user1915746 · Accepted Answer · 2021-09-03T05:29:28.883

I would create a key from the first three values of your array elements and then create a new array using this key. Like this:

<?php

$teamArray = [
  [
    "Team 1",
    "Jack",
    "Daniels",
    "10",
  ],
  [
    "Team 1",
    "Jan",
    "Novak",
    "33",
  ],
  [
    "Team 2",
    "John",
    "Doe",
    "11",
  ],
  [
    "Team 2",
    "Jane",
    "Doe",
    "18",
  ],
  [
    "Team 1",
    "Jack",
    "Daniels",
    "5",
  ],
  [
    "Team 1",
    "Jan",
    "Novak",
    "33",
  ],
  [
    "Team 2",
    "John",
    "Doe",
    "11",
  ],
  [
    "Team 2",
    "Jane",
    "Doe",
    "18",
  ]
];

$result = [];
foreach ($teamArray as $team) {
  $key = $team[0] . $team[1] . $team[2];
  if (isset($result[$key])) {
    $result[$key][3] += $team[3];
  }
  else {
    $result[$key] = $team;
  }
}

var_dump($result);
var_dump(array_values($result));

This gives you:

array(4) {
  ["Team 1JackDaniels"]=>
  array(4) {
    [0]=>
    string(6) "Team 1"
    [1]=>
    string(4) "Jack"
    [2]=>
    string(7) "Daniels"
    [3]=>
    int(15)
  }
  ["Team 1JanNovak"]=>
  array(4) {
    [0]=>
    string(6) "Team 1"
    [1]=>
    string(3) "Jan"
    [2]=>
    string(5) "Novak"
    [3]=>
    int(66)
  }
  ["Team 2JohnDoe"]=>
  array(4) {
    [0]=>
    string(6) "Team 2"
    [1]=>
    string(4) "John"
    [2]=>
    string(3) "Doe"
    [3]=>
    int(22)
  }
  ["Team 2JaneDoe"]=>
  array(4) {
    [0]=>
    string(6) "Team 2"
    [1]=>
    string(4) "Jane"
    [2]=>
    string(3) "Doe"
    [3]=>
    int(36)
  }
}
array(4) {
  [0]=>
  array(4) {
    [0]=>
    string(6) "Team 1"
    [1]=>
    string(4) "Jack"
    [2]=>
    string(7) "Daniels"
    [3]=>
    int(15)
  }
  [1]=>
  array(4) {
    [0]=>
    string(6) "Team 1"
    [1]=>
    string(3) "Jan"
    [2]=>
    string(5) "Novak"
    [3]=>
    int(66)
  }
  [2]=>
  array(4) {
    [0]=>
    string(6) "Team 2"
    [1]=>
    string(4) "John"
    [2]=>
    string(3) "Doe"
    [3]=>
    int(22)
  }
  [3]=>
  array(4) {
    [0]=>
    string(6) "Team 2"
    [1]=>
    string(4) "Jane"
    [2]=>
    string(3) "Doe"
    [3]=>
    int(36)
  }
}

If you need to remove the keys from your $result array you could use array_value as shown above.

Yeah, but the key will not be unique, as the team names are repeating with same members... — Eduard, Sep 02 '21 at 19:32
I updated my answer using the example data you provided. The result is exactly what you expected. — user1915746, Sep 03 '21 at 05:30

Group array items by multiple values and sum the groups

1 Answers1