Calling vs invoking a function

Solution 1:

Your reference text:

It is common to use the term "call a function" instead of "invoke a function" ... In this tutorial, we will use invoke, because a JavaScript function can be invoked without being called.

Now let me rephrase it:

It is common to use the term "call a function" instead of "invoke a function" ... In this tutorial, we will use the term invoke instead of call, because a JavaScript function can be invoked indirectly like fn.call() and fn.apply() without being called directly like fn().

So, when I do fn(), it's invoked directly and when I do it like fn.call(), it's invoked indirectly but in both cases, the function is being invoked. Otherwise, I see no difference here and I can also say that I can call a function in many ways, for example:

fn(); // I'm calling it
fn.call(); // I'm calling it
fn.apply(); // I'm calling it

So, the difference is semantic but both are interchangeable, IMO. BTW, I wrote a comment above, under the question and I would like to put it here, which is:

IMO, that's a misleading statement. Maybe there are some indication of call/apply or something else but it's totally confusing.

Solution 2:

The difference is semantic and subtle. When you call a function, you are directly telling it to run. When you invoke a function, you are letting something run it.

There is one way to call a function:

myFunction()

Here, you are invoking the function (letting it run) by calling it directly.

There are many ways to invoke a function (given throughout different comments and answers). Here's one example:

function invoker(functionName) {
  functionName() 
}

invoker(myFunction)

Here, by calling invoker, you are invoking myFunction, which is being called indirectly.

Solution 3:

Yes, in most cases we use both to refer the execution of a function.

There are 2 ways to reach place B from your HOME.

Direct/Automatic way (Invoke), i.e. if you choose first way, you do not need to walk. Someone will automatically take you to place B.

Indirect way (Call), i.e. if choose second way, you only need to reach A(by walk). Someone is there at place A to automatically take you to place B.

Have a look at the below image. I think it will clear your doubt.