Fp201 unit5 1

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Fp201 unit5 1

  1. 1. F2037 - PROGRAMMINGFUNDAMENTAL WITH C++Unit 5.1 - Understand The Use Of Function
  2. 2. LEARNING OUTCOMEAt the end of this module, students should be able to: Define a function Explain the following types of function:Built-in function, User-defined function Describe the components of function : a. Function header b. Function body c. Local variable d. Return statement e. Parameters declaration list f. Function prototypes Identify the function calls : call by value, call by reference Write program using functions
  3. 3. INTRODUCTION TO FUNCTION A function is a set of statements that performs a specific task. It can be called from any section in the program and executed. The main advantage in using functions is that the number of lines in a program can be reduced. One long program willl be divided into smaller parts and each of these parts is programmed separately
  4. 4. TYPES OF FUNCTIONS built-in function - system function. User-defined function - Created by the users for their requirements.
  5. 5. Built-in Function User-defined Functionstrlen(“fadzlina”) float purata(float x, float y)atof(s) void panggilan(void)pow(x, y) char response(char ch)
  6. 6. BUILT-IN FUNCTION#include<cmath>#include<iostream>using namespace std;void main(){ double d=100.0, d1=100.5, d2=22.0;//find the square root of the number cout<<"nSquarer Root of" << d<<" is = "<<sqrt(d)<<endl;//find log 10 of the number cout<<"nlog10 for" << d<<" is = "<<log10(d)<<endl;//compute power of two number cout<<"n" << d<<" to the power of "<<d2; cout<<" is = " <<pow(d,d2)<<"nn";}
  7. 7. USER-DEFINED FUNCTION#include <iostream>using namespace std;void kira_luasSegiempat(int, int);void main(){ int p,l; cout<<"Masukkan nilai panjang dan lebar: "; cin>>p>>l; kira_luasSegiempat(p,l);}void kira_luasSegiempat(int panjang, int lebar){ double luas; luas = panjang * lebar; cout<<"Luas segiempat :"<<luas <<endl;}
  8. 8. COMPONENTS OF FUNCTIONa) Function headerb) Function bodyc) Local variabled) Return statemente) Parameters declaration listf) Function prototypes
  9. 9. COMPONENTS OF FUNCTIONFunction Header Has three main parts  The name of the function  The parameters of the function enclosed in paranthesis  Return value typeFunction Body What ever is written with in { } in the above example is the body of the function.
  10. 10. COMPONENTS OF FUNCTIONFunction prototype The prototype of a function provides the basic information about a function which tells the compiler that the function is used correctly or not. It contains the same information as the function header contains.Function definition A function must be defined before it can be used
  11. 11. COMPONENTS OF FUNCTIONLocal variable Variable declared inside main() or functionCall Function Call another function by passing value or referenceReturn statement (return) Return the control back to the function that invoked it
  12. 12. Parameter list List of parameters that can be passed to the function
  13. 13. COMPONENTS OF FUNCTION#include <iostream>using namespace std;int prt(int); //Function prototypeint main() //Define function main(){ int x = 12; //Declaration cout << prt(x); //Calling function return 0; //return 0 to situation} Parameter listint prt(int y) //Function header & Function definition{ return y; //Return value //Function body}
  14. 14. FUNCTION DECLARATION Syntax: function_type function_name (parameter-list) { variable declaration; …… return expression; }
  15. 15. FUNCTION DECLARATION function_type = type of data in C++ function_name = name of function parameter-list  passing parameter value when invoked return  return value or control
  16. 16. IDENTIFY FUNCTION CALLS1. Call by value2. Call by reference
  17. 17. CALL BY VALUE#include <iostream>using namespace std;int main(){ void max_min(int, int); int x =2,y=3; max_min(x,y); cout << "x: " << x; cout << "ny: " << y; return 0;}void max_min(int x, int y){ x= x*x; y= y*y;}
  18. 18. CALL BY REFERENCE#include <iostream>using namespace std;int main(){ void max_min(int&, int&); int x=8,y=1; max_min(x,y); cout << "x: " << x; cout << "ny: " << y; return 0;}void max_min(int& x, int& y){ x= x*x; y= y*y;}
  19. 19. IN CLASS EXERCISE By using a function, write a program that able to receive two double numbers and calculate sum for that numbers (hint: use void function).
  20. 20. SUMMARY Function is a component of the program written to perform a specific task. By using functions, the code written once can be used many times anywhere in the program. As the program is segregated into different smaller modules, it is very easy to correct the errors.
  21. 21. #include<iostream>using namespace std;void kira_jumlah ( ); //fungsi prototypevoid main (){kira_jumlah ();system(“pause”);}
  22. 22. void kira_jumlah ( ){int num_1, num_2, JUMLAH;cout<<“Sila masukan 2 integer :”;cin>>num_1>>num_2;JUMLAH=num_1 + num_2;cout<<“}
  23. 23. FUNGSI YANG TIDAK MEMULANGKAN NILAI TETAPI MENERIMA NILAI#include<iostream>using namespace std;void kira_jumlah ( int, int ); //fungsi prototypevoid main (){int num_1, num_2;cout<<“Sila masukan 2 integer :”;cin>>num_1>>num_2;kira_jumlah (num_1,num_2);system(“pause”);}
  24. 24. void kira_jumlah ( int num_1, int num_2) ){int JUMLAH;JUMLAH=num_1 + num_2;cout<<“JUMLAH 2 integer adalah : “ << JUMLAH;}

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