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JavaScript

Posted by jennifer ray
jennifer ray
7,875 Points

var in Javascript

Hi,

What is the different between : var message = 'Hello World!'; vs var message = ('Hello World!'); They both display the message so should i use brackets or not or do they have no use?

4 Answers

bothxp
bothxp
16,510 Points
bothxp
bothxp
16,510 Points

I think that we need to be a little careful because we do some times use parentheses when setting a variable.

var test = 10 + (1 / 10);

is different to

var test = (10 + 1) / 10;

and if you try

var test2 = (10);
var test3 = 10;

then you will find that both test2 & test3 evaluate to 10.

So I think the question of why do we not use the ( ) is an interesting one and other than saying that it's just not the way you would expect to see JavaScript written I haven't been able to find a description as to why it is 'wrong'.

Roy Penrod
Roy Penrod
19,810 Points

Good point, boxthp.

I didn't take into account the math situation. It probably doesn't help that I'm answering questions while working on my own project. :-)

And I'm not saying it doesn't work when you include the parentheses, just that you shouldn't do it because it's against the norm. A large part of development is making sure your code can be understood and maintained in a team environment.

Roy Penrod
Roy Penrod
19,810 Points
Roy Penrod
Roy Penrod
19,810 Points

When you're setting a variable in JavaScript, you do not use the parentheses. For your example, you would use:

var message = "Hello World!";

The parentheses are used when you're calling a function. For example:

console.log(message);
Peter Smith
Peter Smith
12,347 Points
Peter Smith
Peter Smith
12,347 Points

Hey! In your example parentheses act like they do in in math, signifying that what is inside them should be evaluated first.

You wouldn't use them when creating a string. var message = "Hello World!" is the common way of doing it.

jennifer ray
jennifer ray
7,875 Points
jennifer ray
jennifer ray
7,875 Points

Thank you so much everyone for clearing up my question :)