Call to a member function extension() on null

This error message “call to a member function extension() on null” occurs when you attempt to call a method on a variable that is null or has not been properly initialized. In PHP, object-oriented programming allows you to define classes and create objects from those classes. Each object is an instance of a class, and it has its own set of properties and methods.

When you create an object, you need to make sure it is properly instantiated before calling any methods on it. If the object is null or has not been created, you will encounter this error. Let’s take a look at an example:

    
      // Define a class
      class MyClass {
          public function doSomething() {
              return "Hello, world!";
          }
      }
      
      // Create an instance of the class
      $myObject = null;
      
      // Call the method on the object
      echo $myObject->doSomething();
    
  

In the example above, we define a class called “MyClass” with a single method called “doSomething()”. Then, we create a variable called “$myObject” and set it to null instead of instantiating it as an object of the class. Finally, we attempt to call the “doSomething()” method on the null object, which results in the mentioned error.

To fix this error, you need to properly instantiate the object before calling its methods. Here’s an updated example:

    
      // Define a class
      class MyClass {
          public function doSomething() {
              return "Hello, world!";
          }
      }
      
      // Create an instance of the class
      $myObject = new MyClass();
      
      // Call the method on the object
      echo $myObject->doSomething();
    
  

This time, we create an instance of the class using the “new” keyword, and then we call the “doSomething()” method on the instantiated object. Now, the code will execute without any errors and will output “Hello, world!”.