Executing functions in JavaScript

Question

Executing functions in JavaScript

When it comes to calling a method in JavaScript, there are two main ways:

myFunc(params);
obj.myFunc();

Now, let's delve into some questions surrounding these methods:

What exactly is the difference in accessing values (for params/obj) inside myFunc() for each of these approaches?
In the first case, if we use "this" inside myFunc(), it would refer to the global object (window). But how does "this" behave in the second case?
What are the different use cases for opting for one of these techniques over the other?

Feel free to mention any other significant distinctions between these two calling methods as well.

javascript

Answer 1

Answer №1

Without sufficient information provided, I will make assumptions about your two function calls:

1. myFunc(params)
2. obj.myFunc()

It is assumed that the above calls correspond to the following definitions of myFunc() and obj.myFunc():

function myFunc(params) { }

var obj = {
    myFunc: function() { }
};

The first call myFunc(params) invokes the global function myFunc() with params as the parameter. In this case, this will point to the global object which is typically window in browsers (You can confirm this by checking if window.myFunc === myFunc, yielding true)

For the second call obj.myFunc(), it is a call to the method myFunc() within the obj object. Here, this refers to obj, and not window.

As for use cases, it ultimately depends on your overall design. However, utilizing global functions is generally discouraged due to their potential to clutter the global namespace (e.g., accidentally redefining the global myFunc() without realizing it).

The second approach is often employed when creating a pseudo javascript namespace

Answer 2

Without sufficient information provided, I will make assumptions about your two function calls:

1. myFunc(params)
2. obj.myFunc()

It is assumed that the above calls correspond to the following definitions of myFunc() and obj.myFunc():

function myFunc(params) { }

var obj = {
    myFunc: function() { }
};

The first call myFunc(params) invokes the global function myFunc() with params as the parameter. In this case, this will point to the global object which is typically window in browsers (You can confirm this by checking if window.myFunc === myFunc, yielding true)

For the second call obj.myFunc(), it is a call to the method myFunc() within the obj object. Here, this refers to obj, and not window.

As for use cases, it ultimately depends on your overall design. However, utilizing global functions is generally discouraged due to their potential to clutter the global namespace (e.g., accidentally redefining the global myFunc() without realizing it).

The second approach is often employed when creating a pseudo javascript namespace

Answer 3

Answer №2

Allow me to address your queries:

3- Situations: utilizing your_obj.function(): this approach is commonly employed in single-page web applications or when dealing with multiple modules on a single page that need to be kept separate for maintenance purposes. On the other hand, myfunction(args) is typically used globally.

2 - You can trigger it by calling: window.your_obj.function()

1 - I'm uncertain about what you're referring to :)

These are solely my personal views.

Answer 4

Allow me to address your queries:

3- Situations: utilizing your_obj.function(): this approach is commonly employed in single-page web applications or when dealing with multiple modules on a single page that need to be kept separate for maintenance purposes. On the other hand, myfunction(args) is typically used globally.

2 - You can trigger it by calling: window.your_obj.function()

1 - I'm uncertain about what you're referring to :)

These are solely my personal views.

Executing functions in JavaScript

Answer №1

Answer №2

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