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e builds an object named deep_thought, sets its the_answer property to 42, and creates an ask_question method. When deep_thought.ask_question() is executed, JavaScript establishes an execution context for the function call, setting this to the object referenced by whatever came before the last ”.”, in this case: deep_thought. The method can then look in the mirror via this to examine its own properties, returning the value stored in this.the_answer: 42. Constructor

Likewise, when defining a function to be used as a constructor with the new keyword, this can be used to refer to the object being created. Let’s rewrite the example above to reflect that scenario:

Instead of explicitly creating the deep_thought object, we’ll write a function to create BigComputer objects, and instantiate deep_thought as an instance variable via the new keyword. When new BigComputer() is executed, a completely new object is created transparently in the background. BigComputer is called, and its this keyword is set to reference that new object. The function can set properties and methods on this, which is transparently returned at the end of BigComputer’s execution.