A function is a sequence of instructions with a defined start and end, and lists of variables that it gets, uses and returns.
Computer programs are sequences of instructions that tell the computer what to do. A sequence of instructions must have a defined start and end. The instructions operate on variables. The function defines the variables that the function takes, uses and returns.
Parts
- Name
- Parameters – input variables
- Return variable type
- Local variables
- Lines – instructions
- Comments
Name
The name of the function.
For more information, see identifiers.
Parameter
A parameter is a variable that the calling function sets.
The function can modify the parameters.
For more information, see Variables.
Return variable type
The return variable is a variable that is set by the function and read by the calling function.
The function specifies the type of the return variable.
For more information, see Variables.
Local Variable
A variable used by the function itself.
For more information, see Variables.
Line
One or more instructions that tell the computer what to do.
For more information, see Line.
Return line
A line that specifies or creates the data that is returned from the function.
For more information, see Line.
Comment
Comments are text that explains or describes the instructions of a function to a person reading the program.
For more information, see Comments.