Question: I created a method for custom validation and I can not return true value from this method. 
This is my method:

```
requiredFileType(categoryList: CategoryModel[]) {
    return function (control: FormControl) {
      const file = control.value;
      if (file) {
        const extension = file;

        for (let i = 0; i < categoryList.length; i++) {

          for (let j = 0; j < categoryList[i].productModel.length; j++) {
            for (let k = 0; k < categoryList[i].productModel[j].imageProduct.length; k++) {
              console.log(categoryList[i].productModel[j].imageProduct[k].image_path);
              if (categoryList[i].productModel[j].imageProduct[k].image_path.includes(extension)) {
                console.log(categoryList[i].productModel[j].imageProduct[k].image_path);
                return {

                  requiredFileType: null
                };
              }
            }

          }

        }
        return {
          requiredFileType: true
        };
      }

      return {
        requiredFileType: true
      };
    };
  }

```

I do not the understend, I do not have an error, my loop work good but when need return true method return null;

This is my FormControl:

```
 'image': new FormControl(image, this.requiredFileType(this.categoryList)),

```

Answer: 
The task says that if the age is out of range, you should set it to the string `unset`. Calling `unset($w)` doesn't do that. Change that to:

```
$w = "unset";

```
I think it here: 

```php
 return "$this->name at the age of $this->age is a user of $this->site";

// it should be : (i think)

return $this->name . "at the age of " . $this->age . " is a user of " . $this->site;

```

Hope it helps