User-Defined Functions

Under Private create the functions signature:

• Give the function a name that is not a reserved word - Function Gender
• Add parameters as needed starting with a p with their data types - Function Gender(pID:string)
• Add the Function's output data type to the end - Function Gender(pID:string): string;
• Push <Ctrl><Shift><c> to create the skeleton code

In the skeleton code:

• Code what your function should to.
• Remember result needs a value.
• You can use result as a variable, you do not need another local variable to hold the value of result first.
• The result must match the data type of the function - in this case string. The result can be any data type.
• You can use the parameter and do not need to assign it to a local variable.
• Functions may have their own local variables.
• Functions should NOT access objects on the form. Parameters should be used to pass values.

Call statements:

• Functions should be called within another statement. These could include:
  1. Assignment statements - sGender := Gender(sID);
  2. Conditions in if, case or loops. - if Gender(sID) = 'Female' then
  3. Part of output - lblOut.Caption := 'Gender: '+Gender(sID);
• The local variables that are used in the call statement are called arguments. Arguments need to:
  1. Match the data type of the parameter.
  2. Send the same number of arguments as there are parameters.
  3. Send them in the same order as the parameters.
• The place where the call statement is used needs to match the data type of the function's result. If the function result is a string data type, the variable it is assigned to needs to be of string data type.