The role and difference of call () and apply ()

　　　Call, Apply is a method of Function.prototype, which is implemented internally by the JavaScript engine because it belongs to Function.prototype, so each function object instance, that is, each method has a call , apply property. As a property of the method, the use of them is of course a method. These two methods are easy to confuse, because they work the same way, but only in different ways.

The same thing: they all have the same effect.

Different points: Their parameters are different

Call (THIS,ARG1,ARG2,ARG3);

Apply (this,arguments);

Apply has the same effect as call.

Call, the role of apply is to borrow someone else's way to invoke, just like calling their own.

function Add (b) {            alert (a+b);        }     function Sub (b) {            alert (a-b);        }    Add.call (Sub,3,1);    Add.apply (sub,[3,1]);

Their differences are written in the parameters of the call, respectively. The argument to apply is an array

The role and difference of call () and apply ()