Naming variables in JavaScript

The problem

How should I name the variables in my JavaScript code?

The solution

• Variable names must start with a letter, an underscore (_) or a dollar sign ($).
• Variable names cannot contain spaces.
• Variables cannot be the same as reserved keywords such as if or const.
• By convention, JavaScript variable names are written in camelCase.
• Variables should be given descriptive names that indicate their content and usage (e.g. sellingPrice and costPrice rather than x and y).
• As JavaScript variables do not have set types, it can be useful to include an indication of the type in the name (e.g. orderNumber is obviously a numeric ID, whereas order could be an object, a string or anything else).