Names used to store values are often referred to as Variable Names or Variables . The result of any Vision expression can be saved into a variable. Note that the assignment messages are formed using the two characters ' '. You can save the results of any Vision expression by assigning the expression to a variable name. You have complete discretion over the names you use.
Names can contain any number of characters.
You should choose names that are easy to remember and somewhat descriptive. Any information that you save into a variable is available for the remainder of your session or until you redefine the variable. One additional fact is needed to complete this discussion of variable assignment. In many cases, you can use the two forms interchangeably. Note that updating a variable is identical to updating a fixed property .