Rules for Naming JS Variables:

  1. Variable names can only contain letters, digits, underscores, and dollar signs.
    For example, $my_1stVariable
  2. Variables must begin with a letter, underscore, or dollar sign.
    For example, $name, _name or name
  3. Variable names are case sensitive.
    For example, myVar and myvar are different variables.
  4. Variable names should not be JavaScript reserved words.
    For example, you cannot use words like var, const, or let as variable names.

5 legal variable names:

  1. camelCaseName.
  2. $price
  3. _age.
  4. variable123.
  5. [legal_variable.]

5 illegal variable names:

  1. 123name
  2. name-age
  3. var,const,let
  4. true-or-false-value.
  5. @name