Practice Exercises #8

Transcription

1 Practice Exercises #8 Chapter 6 Functions Page 1 Practice Exercises #8 Functions Related Chapter Chapter Title 6 Functions STUDENT LEARNING OUTCOMES: Upon completion of this practical exercise, a successful student will be able to: draw a flowchart to find the factorial of a positive integer, declare a function, call a function, define a function, write a program to declare, call and define a function to calculate the factorial of a positive integer test the written program in one of Computer Labs. Questions 1. Draw a flowchart to calculate the factorial of a positive integer: 2. Write a program using a function. The program is to print the factorial for a given integer number n. You should have a function to calculate the factorial of that introduced number. The main program coordinates the process of inputting values and calling this function as necessary.

2 Practice Exercises #8 Chapter 6 Functions Page 2 Flowchart START N yes N=0 Fact=1 no Fact=1 Fact=Fact*I I=I+1 I< N yes no N, Fact END

3 Practice Exercises #8 Chapter 6 Functions Page 3 Program // Function prototypes #include <iostream> using namespace std; double factorial(int); int main( ) int n; double result; cout << "Enter a value for n: "; cin >> n; result = factorial(n); cout << "\n The factorial of n is " << result<< endl; return(0); double factorial(int m) int i; double fact; fact=1; if (m==0) fact=1; return(fact); for (i=1;i<=m;i++) fact=fact*i; return(fact);

4 Practice Exercises #9 Chapter 6 Functions Page 4 Practice Exercises #9 Pass-by-Value and Pass-by-Reference Related Chapter Chapter Title 6 Functions STUDENT LEARNING OUTCOMES: Upon completion of this practical exercise, a successful student will be able to: Apply passing arguments by value and by reference, write programs calling functions and passing arguments by value and by reference, test the written programs in one of Computer Labs. Questions 1. Write a program using two functions. The program is to print the area of a rectangle for a given input length and width. One of these function should be called from the main program by pass-by-value arguments and the second by pass-by-reference arguments. Try to use some mechanisms to detect the difference between the two types of calls. The main program coordinates the process of inputting values, calling these functions and printing outputs on the screen.

5 Practice Exercises #9 Chapter 6 Functions Page 5 // Calculate the area of a rectangle // Pass-by-Value and Pass-by-Reference #include <iostream> using namespace std; // Function prototype float area1(float,float); float area2(float &,float &); main() float x,y,surf; cout << "Enter values for length x and width y: "; cin >> x >> y; cout <<endl; cout << "Value of x and y before functions calls"<< endl; cout << "x=" << x << endl; cout << "y=" << y << endl; cout <<endl; surf = area1(x,y); cout << "Pass By Value"<< endl; cout << "Rectangle1 area is " << surf << endl; cout << "Value of x and y after Pass-by-Value call"<< endl; cout << "x=" << x << endl; cout << "y=" << y << endl; cout <<endl; surf = area2(x,y); cout << "Pass By Reference"<< endl; cout << "Rectangle2 area is " << surf << endl; cout << "Value of x and y after Pass-by-Reference call"<< endl; cout << "x=" << x << endl; cout << "y=" << y << endl; cout <<endl; return(0); // End of main

6 Practice Exercises #9 Chapter 6 Functions Page 6 // Function Definitions_ Pass By value float area1(float x, float y) float surf1; //local variable x=x+1; y=y+1; surf1 = x * y; return(surf1); // Function Definitions_ Pass By Reference float area2(float &x, float &y) float surf2; //local variable x=x+1; y=y+1; surf2 =x*y; return(surf2); Program Output Enter values for length x and width y: 2 4 Value of x and y before functions calls x=2 y=4 Pass By Value Rectangle1 area is 15 Value of x and y after Pass-by-Value call x=2 y=4 Pass By Reference Rectangle2 area is 15 Value of x and y after Pass-by-Reference call x=3 y=5 Press any key to continue

7 Practice Exercises #10 Chapter 6 Functions Page 7 Practice Exercises #10 Functions (Cont.) Related Chapter Chapter Title 6 Functions STUDENT LEARNING OUTCOMES: Upon completion of this practical exercise, a successful student will be able to: call a function, define a function, write a program to declare, call and define a function, test the written programs in one of Computer Labs Questions 1. Write two functions to calculate the areas of a rectangle and a square respectively. The main program coordinates the process of inputting values, calling these functions and printing the corresponding outputs on the screen.

8 Practice Exercises #10 Chapter 6 Functions Page 8 #include <iostream> #include <math.h> #include <iomanip> using namespace std; Program // Function prototypes float RectangleArea(float,float); float SquareArea(float); main() float length, width, side; float arearec=0.0; float areasq=0.0; cout << "\n Enter the rectangle length: "; cin>>length; cout << "\n Enter the rectangle width: "; cin>>width; cout <<"\n Enter the squre side: "; cin>>side; arearec=rectanglearea(length, width); areasq=squarearea(side); cout<<"\n"; cout<<"\noutput Data\n"; cout << "Rectangle Length: "<<length<<endl; cout << "Rectangle Width: "<<width<<endl; cout << "Square side: "<<side<<endl; cout<<"\n"; cout << "\ntrectanglearea = " << arearec<< endl; cout << "Square Area = " << areasq<< endl; cout<<"\n"; return(0); // End main

9 Practice Exercises #10 Chapter 6 Functions Page 9 // function to calculate the area of a rectangle float RectangleArea(float length1, float width1) float area; //local variable area=length1*width1; return(area); // function to calculate the area of a square float SquareArea(float side1) float area; //local variable area= side1*side1; return(area);

10 Practice Exercises #11 Chapter 6 Passing Arrays to Functions Page 10 Practice Exercises #11 Passing Arrays to Functions Related Chapter Chapter Title 6 Functions STUDENT LEARNING OUTCOMES: Upon completion of this practical exercise, a successful student will be able to: call a function, define a function, pass an array to function test the written program in one of Computer Labs Questions Write a main program passing an array to functions. These functions should accomplish the following tasks: Calculate the sum of even elements in a two-dimensional array. Calculate the sum of odd elements in a two-dimensional array. The main program coordinates the process of inputting values, calling these functions and printing the corresponding outputs on the screen.

11 Practice Exercises #11 Chapter 6 Passing Arrays to Functions Page 11 Program // Passing arrays and individual array elements to functions #include <iostream> using namespace std; int evenarray(int [][2], int, int); int oddarray(int [][2], int, int); main() const int row = 3; const int col = 2; int a[row][col]; int i,j; cout << endl << endl; // Input Array Elements cout << "\n Iutput Data "<< "\n"; cout << endl; for ( i=0; i<row; i++) for ( j=0; j<col; j++) cout << "matrix[" << i <<","<<j<< "]: "; cin >> a[i][j]; cout << endl; cout << endl << endl << endl; cout << "\noutput Data "<< "\n"; cout << endl; cout << "\n Sum of even elements = " <<evenarray(a, row, col)<<endl; cout << "\n Sum of odd elements = " <<oddarray(a, row, col)<<endl; cout << endl << endl << endl; return(0);

12 Practice Exercises #11 Chapter 6 Passing Arrays to Functions Page 12 // function to calculate the sum of even elements in a two-dimensional array int evenarray(int b[][2], int row1, int col1) int max=0; int i,j; int s1=0; for ( i=0; i<row1; i++) for ( j=0; j<col1; j++) if (b[i][j]%2==0) return(s1); s1=s1+b[i][j]; // function to calculate the sum of odd elements in a two-dimensional array int oddarray(int b[][2], int row1, int col1) int s2=0; int i,j; for ( i=0; i<row1; i++) for ( j=0; j<col1; j++) return(s2); if (b[i][j]%2==1) s2=s2+b[i][j];

13 Practice Exercises #12 Chapter 6 Functions using menu Page 13 Practice Exercises #12 Functions Using Menu Related Chapter Chapter Title 6 Functions STUDENT LEARNING OUTCOMES: Upon completion of this practical exercise, a successful student will be able to: call a function, define a function, write a menu and select items from the menu write switch case structure test the written program in one of Computer Labs Questions Write a main program to calculate the area of some geometric forms. The user should select from a menu the geometric form and input the corresponding values: 1. Trapeze Area "; 2. Circle Area "; 3. Square Area "; Area Calculus Enter your choice (0 to end) "; The input values should be transmitted to the corresponding function for conversion. The function result should be printed by the main program.

14 Practice Exercises #12 Chapter 6 Functions using menu Page 14 #include <iostream> #include <math.h> #include <iomanip> using namespace std; // Function prototypes float TrapezeArea(float,float, float); float CircleArea(float); float SquareArea(float); main() float B, b, h, s; float r; int choice; do // Function to calculate trapeze area float TrapezeArea(float B1, float b1, float h1) float area; //local variable area=((b1+b1)*h1)/2; return area; cout << "\n Area Calculus"; cout<<"\n"; cout << "\n 1. Trapeze Area "; cout << "\n 2. Circle Area "; cout << "\n 3. Square Area "; cout<<"\n"; cout << "\n Enter your choice (0 to end) "; cin>>choice; cout << "\n"; switch(choice) case 1: cout << "\n Enter the trapeze big base: "; cin>>b; cout << "Enter the trapeze little base: "; cin>>b; cout << "Enter the trapeze height: "; cin>>h; cout << "\ntrapeze Area = " << TrapezeArea(B, b, h)<< endl; break; case 2: cout << "Enter the Circle Radius: "; cin>>r; cout << "Circle Area = " <<CircleArea(r)<< endl; break; // Function to calculate circle area float CircleArea(float r1) float area1; //local variable area1= 3.141*r1*r1; return area1; // Function to calculate square area float SquareArea(float s1) float area; //local variable area= s1*s1; return area; case 3: cout << "Enter the square side: "; cin>>s; cout << "Square Area = " << SquareArea(s)<< endl; break; case 0: break; default: cout << "\not in range"<< endl; break; while (choice>0); return(0); // End main

15 Practice Exercises #13 Chapter 6 Functions to Convert Measures Page 15 Practice Exercises #13 Functions to Convert Measures Related Chapter Chapter Title 6 Functions STUDENT LEARNING OUTCOMES: Upon completion of this practical exercise, a successful student will be able to: call a function, define a function, write a function to convert from one measure to another, test the written program in one of Computer Labs Questions Write a main program which calls two functions to convert values from kilograms to grams and from meters to centimeters respectively. The main program asks the user for inputs. Thereafter, the main program calls the functions and displays the result.

16 Practice Exercises #13 Chapter 6 Functions to Convert Measures Page 16 #include <iostream> #include <math.h> #include <iomanip> using namespace std; // Function prototypes float convweight(float); float convdist(float); int main() float w, d; cout << "\n Enter the weight in kg: "; cin>>w; cout << "Enter the distance in m: "; cin>>d; cout<<"\n"; cout<<"\n Output Data \n"; cout << " Weight in kg: "<<w<<endl; cout << " Distance in m: "<<d<<endl; cout<<"\n"; // Function to convert values from kg to gr. int convweight(float w1) int weight; //local variable weight=w1*1000; return(weight); // Function to convert values from m to cm. int convdist(float d1) int dist; //local variable dist=d1*100; return(dist); cout << "\n Weight in g = " <<convweight(w)<< endl; cout << "\n Distance in m = " <<convdist(d)<< endl; cout<<"\n"; return(0); // End main