Information Technology Reference
In-Depth Information
and
zip-code
could have been defined using the keyword
character
rather than
integer
since each number is included in the character set. The last line
balance
signed
decimal
(6.2)
introduces two new keywords,
signed
and
decimal
.
Since the account balance could be negative at times and it does involve cents as well as
dollars, we need to spell that out. The variable
signed
allows for negative as well as positive numbers, while
decimal
(6.2)
indicates that the field has 6 digits to the left of the decimal point and 2 to the right. If the
balance happened to be $16.20, it would be on the file as
00001620,
and because the field has a sign, the program knows that this is the positive value of
16.20.
It knows exactly where the decimal point is even though it is not on the file.
This structure will be used in the first program that we consider and we'll be using
other structures as we need them. This will enable us to read a file and access specific
fields in each record. The keyword
structure
merely says we have a piece of a file, namely a record, and this record itself consists of
different things. These are nothing more than the fields that make up the record. We can
access the entire record or individual elements of it.
