1, 'b' => 2]; $team2 = ['c' => 3, 'd' => 4]; $team3 = ['e' => 5, 'f' => 6]; $teams = [$team1, $team2, $team3]; $teamRanks = [3, 1, 2]; $sortedRanks = RankSorter::sort($teams, $teamRanks); $this->assertEquals($team2, $sortedRanks[0]); $this->assertEquals($team3, $sortedRanks[1]); $this->assertEquals($team1, $sortedRanks[2]); // Since we are also using a return $this->assertEquals($team2, $teams[0]); $this->assertEquals($team3, $teams[1]); $this->assertEquals($team1, $teams[2]); // Since we're passing a reference, but also get a return $this->assertEquals($teams[0], $sortedRanks[0]); $this->assertEquals($teams[1], $sortedRanks[1]); $this->assertEquals($teams[2], $sortedRanks[2]); } }