a , an

Article, one

• The word a or an can be used in place of one in conjunction with a number word or a unit.
  • a million
  • an hour
  • an inch

Keyword

The word a or an is a keyword that is part of a number of commands, operators, and expressions.

• is a, is not an

  • the "is a" operator is used to determine whether a variable or value is of a particular type

    Example:

    if it is a number then add it to total

• a new object, create an object

• there is a, there is not an

• an empty list