Naming Variables

  • Remember that we declare a new variable by typing the let keyword and then assigning a name to the variable.
  • A variable’s name is also known as an identifier.
let blank;

Rule 1

  • Names must begin with a letter, an underscore, or a dollar sign $ (best coding practice starts names with a lowercase letter).
  • The letter of the first word in an identifier should always be lowercase, and the first word of any proceeding words should be uppercase.
// This practice is called camelcase. Ex: 
// myVariable, placeHolder, camelCase



Rule 2

  • Names are case sensitive. If you declare a variable with the identifier myVariable, it cannot be accessed by saying myvariable or myVARIABLE

Rule 3

  • Reserved words cannot be used as names.
  • There are a few words used in JS that perform specific actions, such as the let keyword that tells the computer we are declaring a new variable
  • Reserved words include JavaScript keywords, and all of the words included here:

Reserved words example

            let monthlyRent = 600;
            let carNote$ = 300;
            let home_address = "789 Super Fun Ln.";
            let businessAddress2 = "326 City Rd.";
            let lunchTotal$ = 11.49;
  • notice the different types of data assigned


  • Declare new variables and convert the following phrases to an appropriate variable name, using camelCasing and other naming conventions:
  1. annual income
  2. bills to be paid
  3. number of vacation days left
  4. week one
  5. week two
  6. week six