Chapter 17: Lumping Related Data in Records 237
The following bit of code shows that you must first define your record and then create a variable to represent your record:
TYPE EmployeeRecord
FullName AS STRING * 15
Address AS STRING * 25
Phone AS STRING * 14
Salary AS SINGLE
END TYPE
DIM Workers AS EmployeeRecord
The DIM command in the preceding example tells the computer, “Create the variable Workers that can hold data that the record EmployeeRecord defines.”
Only after you define a variable to represent your record can you start stuffing data into the record.
Manipulating Data in Records
To add data to and retrieve data from a record, you need to specify the following two items:
The variable name that represents the record
The variable name inside the record in which you want to store data or from which you want to take data
Storing data in a record
To store data in a record, you need to specify both the variable name (which represents a record) and the specific record variable to use, as in the following example:
RecordVariable.Variable = Data
Suppose that you had a record definition like the following example:
TYPE BomberInfo
NickName AS STRING * 16
MissionsFlown AS INTEGER
Crew AS INTEGER
END TYPE
238 Part IV: Dealing with Data Structures
You define a variable to represent this record as follows:
DIM B17 AS BomberInfo
Then, if you want to store a string in the NickName variable, you use the following command:
B17.NickName = “Brennan’s Circus”
This command tells the computer, “Look for the variable B17 and store the string “Brennan’s Circus” in the NickName variable.”
Retrieving data from a record
You can retrieve stored data by specifying both the record’s variable name and the specific variable that contains the data that you want to retrieve, as follows:
Variable = RecordVariable.Variable
Suppose, for example, that you have the following record definition and a variable to represent that record:
TYPE BomberInfo
NickName AS STRING * 15
MissionsFlown AS INTEGER
Crew AS INTEGER
END TYPE
DIM B24 AS BomberInfo
See how C creates records
Different languages use different ways to create identical data structures. The C programming language creates a record (known as a structure in the C language) as shown in the following example:
struct bomberinfo { char nickname[15] int missionsflown int crew
} B24;
This bit of C code creates the structure (or record) bomberinfo. The bomberinfo structure can store a nickname up to 15 characters, an integer in the variable missionsflown, and another integer in the variable crew. In addition, this code also creates the variable B24 that represents this structure.