Variables Variables let you give names to values and refer to them later. You have already seen variables in many of the examples. The name of a variable must be a sequence of letters, digits and underscores, but it may not begin with a digit. Octave does not enforce a limit on the length of variable names, but it is seldom useful to have variables with names longer than about 30 characters. You should not use them in code you write, except to access Octave's documented internal variables and built-in symbolic constants.
Case is significant in variable names.
The symbols a and A are distinct variables. A variable name is a valid expression by itself. It represents the variable's current value. Variables are given new values with assignment operators and increment operators . See section Assignment Expressions .