Object oriented programming 12 programming steps in cpp and example
- 1. Object Oriented Programming:12 Programming Steps in C++ and Example Program Prof Neeraj Bhargava Vaibhav Khanna Department of Computer Science School of Engineering and Systems Sciences Maharshi Dayanand Saraswati University Ajmer
- 2. 2 Programming Example: Convert Length • Write a program that takes as input a given length expressed in feet and inches – Convert and output the length in centimeters • Input: length in feet and inches • Output: equivalent length in centimeters • Lengths are given in feet and inches • Program computes the equivalent length in centimeters • One inch is equal to 2.54 centimeters
- 3. 3 Programming Example: Convert Length (continued) • Convert the length in feet and inches to all inches: – Multiply the number of feet by 12 – Add given inches • Use the conversion formula (1 inch = 2.54 centimeters) to find the equivalent length in centimeters
- 4. 4 Programming Example: Convert Length (continued) • The algorithm is as follows: – Get the length in feet and inches – Convert the length into total inches – Convert total inches into centimeters – Output centimeters
- 5. 5 Programming Example: Variables and Constants • Variables int feet; //variable to hold given feet int inches; //variable to hold given inches int totalInches; //variable to hold total inches double centimeters; //variable to hold length in //centimeters • Named Constant const double CENTIMETERS_PER_INCH = 2.54; const int INCHES_PER_FOOT = 12;
- 6. 6 Programming Example: Main Algorithm • Prompt user for input • Get data • Echo the input (output the input) • Find length in inches • Output length in inches • Convert length to centimeters • Output length in centimeters
- 7. 7 Programming Example: Putting It Together • Program begins with comments • System resources will be used for I/O • Use input statements to get data and output statements to print results • Data comes from keyboard and the output will display on the screen • The first statement of the program, after comments, is preprocessor directive to include header file iostream
- 8. 8 Programming Example: Putting It Together (continued) • Two types of memory locations for data manipulation: – Named constants • Usually put before main – Variables • This program has only one function (main), which will contain all the code • The program needs variables to manipulate data, which are declared in main
- 9. 9 Programming Example: Body of the Function • The body of the function main has the following form: int main () { declare variables statements return 0; }
- 10. 10 Programming Example: Writing a Complete Program • Begin the program with comments for documentation • Include header files • Declare named constants, if any • Write the definition of the function main
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- 12. 12 Programming Example: Sample Run Enter two integers, one for feet, one for inches: 15 7 The numbers you entered are 15 for feet and 7 for inches. The total number of inches = 187 The number of centimeters = 474.98
- 13. 13 Summary • C++ program: collection of functions where each program has a function called main • Identifier consists of letters, digits, and underscores, and begins with letter or underscore • The arithmetic operators in C++ are addition (+), subtraction (-),multiplication (*), division (/), and modulus (%) • Arithmetic expressions are evaluated using the precedence associativity rules
- 14. 14 Summary (continued) • All operands in an integral expression are integers and all operands in a floating-point expression are decimal numbers • Mixed expression: contains both integers and decimal numbers • Use the cast operator to explicitly convert values from one data type to another • A named constant is initialized when declared • All variables must be declared before used
- 15. 15 Summary (continued) • Use cin and stream extraction operator >> to input from the standard input device • Use cout and stream insertion operator << to output to the standard output device • Preprocessor commands are processed before the program goes through the compiler • A file containing a C++ program usually ends with the extension .cpp
- 16. Assignment • Describe in detail the programming steps for converting length in Feet and inches to centimeters • Explain the importance of “program planning and design documentation” before implementing the code / actual program