Variables

• Like any programming language JavaScript has variables.
• Store data items used in script.
• Strict rules governing how you name your variables:
  • names must begin with a letter, digit or underscore;
  • you can't use spaces in names
  • names are case sensitive so the fred, FRED and frEd all refer to different variables,
  • you can't use a reserved word as a variable name, e.g. var.