Code runs when defining a variable?

Question

I was watching one of the tutorials, and I realized when the instructor defined a variable like this,
javascript
var http = require("http")

the code in the variable runs. Why is this? I always thought when you defined a variable, you have to use it somewhere else to access what is stored in it. Thanks if someone could clear this up for me.

eck · Accepted Answer

I am thinking that reason why you  can do this is  so you can write
```js
var http = require("http");
// instead of having to write
var http;
http = require("http");
```
Any time you write a function and include parentheses  at the end, you are telling the browser to run that function, and if the function returns a value that you plan to reuse, this is one of the ways you would do.
Below are some examples of how you can declare the value for a new variable:
```js
// all these variables will equal 4
// simply declaring a variable with a constant value
var w = 4;
// perform operation here. If it was more complex, we might want to create a function for it.                                           
var x = 2 + 2;  
// parentheses will call this anonymous function right here and return 4.
var y = function(){ return 2 + 2; }(); 
// call a function and return value will be the variable's value.
var z = add(2, 2);                                
function add(num1, num2) {
  return num1 + num2;
}
```
I hope this helps! :D

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orangebear

orangebear

Code runs when defining a variable?

1 Answer

eck

eck

orangebear

orangebear