Call Methods for Javascript-function objects

The call method is a method of a function object that has the parameters of another object (and the arguments to be passed to the function object).

Class1.call (Class2) in the code; This means that the this in the CLASS1 function points to the Class2 object, and then executes.

So the last line of code, the print is Class1.

This method is commonly used in this case:

Function A's parameters need a callback function B, in function A to execute the callback function B, need to use call ().

Call Methods for Javascript-function objects