1. 1.2 Function and Class Names
A First Book of C++
1.2 Function and Class Names

2. Function and Class Names
Modular programs
Segments arranged in logical order to form an integrated unit
Module
Segments of modular program
Function: Name of a C++ procedure
Composed of sequence of C++ instructions
Function interface is its inputs and results
Method of converting input to results is encapsulated and hidden within function
A First Book of C++ 4th Edition

3. Function and Class Names (cont'd.)
A First Book of C++ 4th Edition

4. Function and Class Names (cont'd.)
A First Book of C++ 4th Edition

5. Function and Class Names (cont'd.)
Identifiers
Names that convey an idea of the purpose of function or class
Identifier composition rules
First character must be a letter or underscore
Only letter, digit, or underscore may follow
Blank spaces aren’t allowed
Identify component words with initial capitalization
Cannot be C++ keyword
Should be a mnemonic
A First Book of C++ 4th Edition

6. Function and Class Names (cont'd.)
A First Book of C++ 4th Edition

7. Function and Class Names (cont'd.)
Examples of valid identifiers:
grosspay taxCalc
addNums degToRad
multByTwo salesTax
netPay bessel
A First Book of C++ 4th Edition

8. Function and Class Names (cont'd.)
Examples of invalid identifiers:
4ab3 (begins with a number)
e*6 (contains a special character)
while (is a keyword)
A First Book of C++ 4th Edition

9. The main() Function
Each C+ program must have one and only one function named main
Called a driver function because it drives the other modules
A First Book of C++ 4th Edition

10. The main() Function (cont'd.)
A First Book of C++ 4th Edition

11. The main() Function (cont'd.)
First line of function is called header line
What type of data, if any, is returned from function
The name of function
What type of data, if any, is sent into function
Data transmitted into function at runtime are referred to as arguments of function
A First Book of C++ 4th Edition

12. The main() Function (cont'd.)
A First Book of C++ 4th Edition

13. For Now Basic Format Line 1 - // Your Name
Line // Page # and Problem #
Line // Date Assigned
Line int main()
Line {
Line 6 - ? - Indicating "The program begins here" and the last two lines are:
Line 998 – return 0;
Line }
A First Book of C++ 4th Edition