Lecture_Notes_21_22_23

# Lecture_Notes_21_22_23 - Functions A function is a...

This preview shows pages 1–9. Sign up to view the full content.

Functions A function is a subprogram that can act on data and return a value main() { Statement1; func1(); Statement2; func2(); func4(); } func1 _____ _____ return; func2 func3() _____ return; func4 _____ _____ return; func3 _____ _____ return;

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Purpose of Functions? • Modularity – Each function performs a specific task and has independent local variables (does not depend on other functions) • Reuse of code – All of the code in the function is for a specific task. And, just call it when needed
Function Types Functions are of two types: Built-in: These functions are part of compiler package – they are supplied by manufacturer for your use. For example, float pow(float, float) User-defined: These functions you write yourself

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
#include <iostream> #include <cstdlib> using namespace std; void print() { cout<< "Inside print function" <<endl; } int main() { print(); cout<< "main Function" <<endl; print(); system( "PAUSE" ); return 0; } A simple function When you don’t want your function to return a value, you declare its return type to be void .
Purpose of Functions - Example #include <iostream> using namespace std; int main() { double n=0, roundNumber=0; cout<< "Enter n" ; cin>>n; if (n>0) roundNumber= int (n+0.5); else roundNumber= int (n-0.5); cout<< "Rounded Number is " <<roundNumber<<endl; system( "PAUSE" ); return 0; } In this program, all the required statements are part of main function. However, to develop a large program, it is better to construct it from smaller pieces so that each piece can be more manageable

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
1. #include <iostream> 2. using namespace std; 3. int rnd( double n) 4. { 5. if (n>=0) 6. return int (n+0.5); 7. else 8. return int (n-0.5); 9. } 10. int main() 11.{ 12. double n=0, roundNumber=0; 13. cout<< "Enter n" ; 14. cin>>n; 15. roundNumber=rnd(n); //this function round-off decimals 16. cout<< "Rounded Number is " <<roundNumber<<endl; 17. system( "PAUSE" ); 18. return 0; 19.} Purpose of Functions - Example Main function is cleaner and more understandable, less error prone
1. #include <iostream> 2. using namespace std; 3. int rnd( double n) 4. { 5. if (n>=0) 6. return int (n+0.5); 7. else 8. return int (n-0.5); 9. } 10. int main() 11.{ 12. double n=0, roundNumber=0; 13. cout<< "Enter n" ; 14. cin>>n; 15. roundNumber=rnd(n); //this function round-off decimals 16. cout<< "Rounded Number is " <<roundNumber<<endl; 17. system( "PAUSE" ); 18. return 0; 19.} Purpose of Functions - Example return-type name (parameters-list) information coming back information coming into function

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Function definition, return-value, parameter-list, and arguments 1. #include <iostream> 2. using namespace std; 3. int rnd( double n) 4. { 5. statements; 6. return int (n-0.5); 7. } 8. int main() 9. { 10. statements; 11. roundNumber=rnd(n); //this function round-off decimals 12. statements; 13.} The format of function definition is return-value-type function-name ( parameter-list ) { statements; } This is the definition of rnd function return-value-type function-name parameter-list arguments
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### Page1 / 46

Lecture_Notes_21_22_23 - Functions A function is a...

This preview shows document pages 1 - 9. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online