Variables
In normal language, names are (usually) tightly fixed to their values --
- “penny” means 1 cent … it doesn’t change its meaning, and sometimes refer to $8.41 or a time zone or an action
In computing names must change values
- Example: Alpha and Bet in Alphabetize CDs changed
- Names must change values in a program because programs specify a transformation of input into output … as the transformation proceeds the things named change values
variable is term for program names that change value
Variables are analogous to titles in normal language since titles are expected to change values: president, mayor, James Bond