PHP aggregation of a property, of all objects in a class - php

Question

apologies in advance for being a OO noob...
I am trying to write a method to aggregate a property of all objects that exist for a given class. The code below describes what I want to do.
Class TeamMember(){
function SetScore($value) {
$this->score = $value;
}
function GetTotalScoreForTeam() {
//best way to iterate over all the objects to get a sum??????
return totalScore;
}
}
$john = new TeamMember();
$john->SetScore('182');
$paul = new TeamMember();
$paul->SetScore('212');
$totalScore = TeamMember->GetTotalScoreForTeam;
Thanks!

Answer 1

Even if this is not the best way to approach this problem, I think it is the most explaining your problem with your pre-written code:
class TeamMember { // a class is not a function/method; removed the ()
public static $members = array(); // holds the instances
public $score; // It is simply good practice to declare your fields (it is not necessary)
function __construct () {
self::$members[] = $this; // save the instances accessible for your score-calcuating method
}
function setScore ($value) {
$this->score = $value;
}
static function getTotalScoreForTeam () { // a static method is best here
$totalScore = 0;
foreach (self::$members as $member) // foreach over the instances holding list
$totalScore += $member->score;
return $totalScore;
}
}
$john = new TeamMember();
$john->setScore('182');
$paul = new TeamMember();
$paul->setScore('212');
$totalScore = TeamMember::getTotalScoreForTeam(); // for static access, use a :: instead of ->

Answer 2

As Mike B said in the comment you should first group your TeamMember instances in an instance of a Team class and then run some aggregate function to calculate the total score of that particular team, e.g.
<?php
$team1 = Team::create('Team 1')
->add( TeamMember::create('john')->SetScore(182) )
->add( TeamMember::create('paul')->SetScore(212) );
$team2 = Team::create('Team 2')
->add( TeamMember::create('peter')->SetScore(200) )
->add( TeamMember::create('marry')->SetScore(300) );
foo($team1);
foo($team2);
function foo(Team $team) {
$score = $team->membersReduce(
function($v, $e) {
return $v+$e->getScore();
}
);
$members = $team->membersMap(
function($e) {
return $e->getName();
}
);
echo 'team : ', $team->getName(), "\r\n";
echo 'score: ', $score, "\r\n";
echo 'members: ', join(' | ', $members), "\r\n";
}
class TeamMember {
protected $score = 0;
protected $name;
public static function create($name) {
return new TeamMember($name);
}
public function __construct($name) {
$this->name = $name;
}
public function getName() {
return $this->name;
}
public function SetScore($value) {
$this->score = $value;
return $this;
}
public function GetScore() {
return $this->score;
}
}
class Team {
protected $members = array();
protected $name;
public static function create($name) {
return new Team($name);
}
public function __construct($name) {
$this->name = $name;
}
public function getName() {
return $this->name;
}
public function add(TeamMember $t) {
// <-- check if $t already member of team -->
$this->members[] = $t;
return $this;
}
public function membersReduce($fn) {
return array_reduce($this->members, $fn);
}
public function membersMap($fn) {
return array_map($fn, $this->members);
}
}
prints
team : Team 1
score: 394
members: john | paul
team : Team 2
score: 500
members: peter | marry