Understanding Variables

Like any programming language, some method is used to store data into some place holder. These place holders are called variables. Variables are used to store various pieces of data that are used throughout the program. It is recommended to give variables understandable names, making the program more readable and easier to interpret.

For OpenInsight, variables must be 'assigned' a value before they are used in a program. If variables are not assigned some value and they are used, the program will break. Be sure to assign all of the required variables at the top of the program, or at least before they are used later in the program.

Some examples of variable assignment:

            Myvariable = 1

            Myothervariable = 'text is always put between quotes'

            valuex = myvariable

            myvariable = 2

Notice that variables can be assigned to other variables without concern for what the values are. However, be careful not to include variables containing text in mathematical expressions.  Also, when a variable is assigned a new value, the old value is lost unless assigned to another variable.

The Variables screen in the MAPCON Symbolic Editor Window can be used to create variables that are assigned to columns in a table. The table that is used is the same table the report uses as a datasource. When the Variables push-button is clicked, a list of available columns is displayed. Selecting a column will produce one of two results:

VAR1$ = Calculate( columnname )    or

VAR1$ = @RECORD<tablename_columnname>

The first result calculates a symbolic column and assigns the value to the variable VAR1$. The second result gets the value from the variable @RECORD and assigns the value for that column to VAR1$.