JavaScript Variable Casing Best Practices

JavaScript is a loosely-typed case sensitive language.  Technically everything in the language is a variable.  Yes, it may be a string, a function, an array or an object, but everything is a variable at its core.  Because you can make your variables all lowercase or all uppercase or anywhere in between, it’s important for the sake of code readability to have a pattern for how the variables will be cased.

The following is the best practices for variable casing and is useful to encourage a greater consistency in JavaScript code:


For dynamic strings, ints, floats and arrays, use camel casing.

var myVariable = 'This is my string';


Classes should be camel-cased.

var myObject = { hello: 'world' };


Constants are similar to dynamic variables, but the difference is that they should never change once they are set.  Think of these as configuration variables.  Constants should be upper cased with an underscore between each word.

var MY_CONSTANT = ‘I am a constant!’;

Functions and Methods

Functions and methods should both use camel casing.

var myFunction = function(){
   console.log(‘I am a function!’);


Classes look quite a bit like functions, but they are initialized using ‘new’. JavaScript classes should use upper casing.

var MyClass = function(){
   this.alert = function(){
      console.log(‘I am a Class!’);

var getClass = new MyClass();

Obviously, this isn't going to instantly fix all of the coding issues in the world, but follow these guidelines and your code will be just a little more legible!

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