Functions Exercise
Programming Exercise
Functions Programming Exercise P-1
Pointers programming exercise p-2
Program 10:
Write a program that accepts two integer values and passes these values to a function by reference. The function swaps/exchanges these values. The swapped / exchanged values should be displayed in the calling function.
#include<iostream.h> #include<conio.h> main() { void swap(int&, int&); int a, b; clrscr(); cout<<"Enter value of a ? "; cin>>a; cout<<"Enter value of b ? "; cin>>b; swap(a,b); cout<<"Values of a & b after swapping\n"; cout<<"Value of a ="<<a<<endl; cout<<"Value of b ="<<b<<endl; getch(); } // definition of swap() function void swap(int& x, int& y) { int temp; temp = x; x = y; y = temp; }
Program 11:
Write a program that gets three numbers and passes these numbers to a function. The function finds out the largest number and returns this number to the calling function.
#include<iostream.h> #include<conio.h> main() { int max(int, int, int); //function prototype int a, b, c; clrscr(); cout<<"Enter first number: "; cin>>a; cout<<"Enter second number: "; cin>>b; cout<<"Enter third number: "; cin>>c; cout<< "Largest number is: "<<max(a, b, c); getch(); } // definition of max() function int max(int x, int y, int z) { int mx = x; if (y > mx) mx = y; if (z > mx) mx = z; return mx; }
Program 12:
Write a function GCD that has two input parameters and returns the greatest common divisor of the two numbers passed to it. Write a complete C++ program that inputs two numbers and calls the function GCD to compute the greatest common divisor of the numbers entered.
#include<iostream.h> #include<conio.h> main() { int GCD(int, int); int a, b, cd; clrscr(); cout<<"Enter first integer value ? "; cin>>a; cout<<"Enter second integer value ? "; cin>>b; cd = GCD(a, b); cout<<"Greatest common divider is : "<<cd; getch(); } // definition of GCD() function int GCD(int x, int y) { int i, g = 1; for(i = 2;i<=x; i++) if(x%i== 0 && y%i== 0) g = i; return g; }
Program 13:
Write a program by defining a function “qualitypoints” that takes average marks of a student and returns the value as:
// 4 if average is between 90 and 100.
// 3 if average is between 70 and 89.
// 2 if average is between 50 and 69.
// 1 if average is between 40 and 49.
// 0 if average is lower than 40.
#include<iostream.h> #include<conio.h> main() { int qualitypoints(int); int avg; clrscr(); cout<<"Enter average marks ? "; cin>>avg; cout<<"Student's quality points = " <<qualitypoints(avg); getch(); } // definition of qualitypoints() function int qualitypoints(int average) { int grade; if (average >= 90) grade =4; else if (average >= 70) grade =3; else if (average >= 50) grade =2; else if (average >= 40) grade =1; else grade =0; return grade; }
Program 14:
Write a program by defining a function “grade” that takes average marks of a student and returns his/her grade. The function finds out the grade of the student on the basis of following criteria:
// Grade is ‘A’ if average is between 90 and 100.
// Grade is ‘B’ if average is between 70 and 89.
// Grade is ‘C’ if average is between 50 and 69.
// Grade is ‘D’ if average is between 40 and 49.
// Grade is ‘F’ if average is lower than 40.
#include<iostream.h> #include<conio.h> main() { char grade(int); int avg; clrscr(); cout<<"Enter average marks ? "; cin>>avg; cout<<"Grade of student = " <<grade(avg); getch(); } // definition of grade() function char grade(int average) { char gr; if (average >= 90) gr ='A'; else if (average >= 70) gr ='B'; else if (average >= 50) gr ='C'; else if (average >= 40) gr ='D'; else gr ='F'; return gr; }
Program 15:
Write a program that prompts the user to enter a number and calls a function Factorial() to compute its factorial. Write the function Factorial() that has one input parameter and returns the factorial of the number passed to it.
#include<iostream.h> #include<conio.h> void main(void) { long Factorial(int), ans; int x; clrscr(); cout<<"Enter integer value ? "; cin>>x; ans = Factorial(x); cout<<"Factorial of "<<x<< "is"<<ans; getch(); } // definition of Factorial() function long Factorial(int n) { long f=1; for(; n>=1; n--) f = f*n; return f; }