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PHP Object-Oriented PHP Basics Building a Collection Collection Objects

How to return an collection array of house objects that match the passed color parameter.

This is bit confusing because i don't know why it's not working. I'm getting each house and then compare the walls/roofs with the passed color. If it's true it adds the house to the output array.


// add code below this comment
class Subdivision
  public $output = array();
    public $houses = array();
  public function filterHouseColor($color)
    foreach ($this->houses as $house){
      if($this->roof_color === $color || $this->wall_color === $color){
        $this->output[] = $house;
    return $this->output;


This part here was wrong:

if($this->roof_color === $color || $this->wall_color === $color){

1 Answer

Jennifer Nordell
Jennifer Nordell
Treehouse Teacher

Hi there, Damian Toczek ! You're doing terrific and you're super close! Take a look at this line:

foreach ($this->houses as $house)

This is set up just fine. But it also means that for every iteration through that collection, the individual item is assigned to the variable $house. Then in the very next line, you set up your if statement just brilliantly, but you're comparing the roof_color and wall_color of this. You should be comparing the roof_color and wall_color of the $house.

Making that change will cause this to pass. Hope this helps! :sparkles:

Hi, thank you, I've already noticed that.