When we are writing a program, we may have a piece of information that will need to be referred to from other places in our program. Values and variables are used for this. They are defined using the keywords val and var, respectively. We can think of vals and vars as boxes containing items of data. A var is a box from which the data may be removed and replaced with some other data item. With a val, however, the data item is set once and can never be replaced.
6.1 Using vars
One common use of vars
is to store the ...
