PHP, Fatal error: Call to undefined method, why?

Question

I have a simple php structures.

class Ingredient and class Ingredients, i have this code:

class Ingredient
{   
   public function objectIsValid()
           


        

Answer 1

function __construct(){   $ingObject = new Ingredient();   }

ought to be

function __construct(){   $this->ingObject = new Ingredient();   }

In the first case you're setting a local variable, not a field, so it remains null. Then on the validateData you invoke a method on a null variable.

I'm assuming you snipped some code, because your Ingredient class doesn't make sense (there's a $validate variable there that isn't defined).