Coffee Script Variables - CoffeeScript

What is Coffee Script Variables?

Variables are nothing but named containers. you can place information into these containers after which consult with the records using the name of its container.

In JavaScript, earlier than using a variable, we need to claim and initialize it (assign value). Unlike JavaScript, even as creating a variable in CoffeeScript, there is no want to declare it the usage of the var keyword. We sincerely create a variable just by way of assigning a cost to a literal as shown beneath.

Example

In the following CoffeeScript code, we've defined variables name and age, of string and number data types respectively. Store it in a document with the name variable_example.coffee.

Compiling the code

Bring together the above CoffeeScript code by using executing the following command inside the command spark off.

On compiling, a JavaScript report named variable_example.js will be generated with the subsequent content. right here you could examine that the compiler declared the variables (age and name) the usage of the var keyword on behalf people.

Variable Scope

The scope of a variable is the area of your program wherein it is described. JavaScript and CoffeeScript variables have most effective two scopes.

  • Global Variables − A global variable has a worldwide scope because of this it may be used anywhere in your JavaScript code.
  • Local Variables − A nearby variable might be visible best inside a feature wherein it is defined. Feature parameters are always local to that function.

The problem with Variables in JavaScript

In JavaScript, every time we define a variable without the use of the var keyword, it is created with worldwide scope. This causes numerous issues. consider the subsequent example –

On executing, the above JavaScript gives you the following output −

in the above example, we have created a variable named I within the global space and assigned the price 10 to it. And within the function, in an attempt to create a nearby variable with the identical name, we've got declared as i=20; without var keyword. Since we neglected the var keyword, the value of the global variable i is reassigned to 20.

For this reason, it is recommended to declare variables using the var keyword.

Variable Scope in CoffeeScript

Whenever we collect a CoffeeScript record, the CoffeeScript compiler creates an anonymous feature, and within that function, it Trans compilers the CoffeeScript code into JavaScript line via a line. (If we want, we can do away with the pinnacle level feature wrapper the use of the -b or --bare option of the collect command) every variable that we create is asserted the use of the var keyword within the nameless characteristic and hence, through default, each variable is nearby in CoffeeScript.

Anyway, if we want, we can declare a variable with global namespace. We can do it explicitly as shown below.

CoffeeScript Variable Names (Literals)

At the same time as naming your variables in CoffeeScript, hold the subsequent guidelines in mind.

You need to no longer use any of the CoffeeScript reserved keywords as a variable name. Those keywords are cited in the next phase. As an instance, break or Boolean variable names are not legitimate.

CoffeeScript variable names should not start with a numeral (0-nine). They should begin with a letter or an underscore character. For instance, 123test is an invalid variable name; however, _123test is a valid one.

CoffeeScript variable names are case-sensitive. as an instance, call and name are distinctive variables.

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