Multiple conditions for if statement in C / C++ While loop in C / C++ with examples
In this tutorial, we will learn about the C / C++ while loop and its working with the help of some examples. This is one of the basic knowledge in C / C++ programming language, so please learn it carefully.
Top 20 while loop in C / C++ with examples
Here, we will implement examples using while loop in C / C++ from basic to advanced. For each example, we will implement with two different languages C and C++.
Example 1: Printing numbers from 1 to 200 with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int i = 1;
cout<<"Numbers from 1 to 200:\n ";
while (i <= 200) {
cout << i << " ";
i++;
}
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
int main(void) {
int i = 1;
printf("Numbers from 1 to 200: \n");
while (i <= 200) {
printf("%d ", i);
i++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 2: Displaying a text 10 times with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int i = 1;
cout<<"Displaying a text 10 times with for while in C / C++. \n\n";
while (i <= 10) {
cout <<"Hello, I'm learnc.net\n";
i++;
}
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
int main(void) {
int i = 1;
printf("Displaying a text 10 times with for while in C / C++. \n\n");
while (i <= 10) {
printf("Hello, I'm learnc.net\n");
i++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 3: Find the sum of first n Natural Numbers with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int num, sum, i = 1;
sum = 0;
cout << "Enter a positive integer: ";
cin >> num;
while(i <= num) {
sum += i;
i++;
}
cout << "Sum = " << sum << endl;
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}
C programming:
#include <stdio.h>
int main(void) {
int num, sum, i = 1, j = 1;
sum = 0;
printf("Enter a positive integer: ");
scanf("%d", &num);
printf("Numbers from 1 to %d: ",num);
while (j <= num) {
printf("%d ", j);
j++;
}
while (i <= num) {
sum += i;
i++;
}
printf("\nSum = %d\n", sum);
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 4: Display elements of array using while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int arr[]={19, 2, 17, 1, 2000, 2003};
int i = 0;
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
cout<<"Elements of array: ";
while(i<6){
cout<<arr[i]<<" ";
i++;
}
cout<<"\n\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
int main(void) {
int arr[]={19, 2, 17, 1, 2000, 2003};
int i = 0;
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
printf("Elements of array: ");
while(i<6){
printf("%d ",arr[i]);
i++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 5: Displaying even numbers from 1 to n with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int n, i = 1;
cout<<"Enter number n: ";
cin>>n;
cout<<"Even numbers from 1 to "<< n<<" is: \n";
while(i <= n){
if(i % 2 == 0)
cout<<i<<" ";
i++;
}
cout<<"\n\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
int main(void) {
int n, i = 1;
printf("Enter number n: ");
scanf("%d", &n);
printf("Even numbers from 1 to %d is: ", n);
while(i <= n){
if(i % 2 == 0)
printf("%d ", i);
i++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 6: Displaying odd numbers from 1 to n with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int n, i = 1;
cout<<"Enter number n: ";
cin>>n;
cout<<"Odd numbers from 1 to "<< n<<" is: \n";
while(i <= n){
if(i % 2 == 1)
cout<<i<<" ";
i++;
}
cout<<"\n\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
int main(void) {
int n, i = 1;
printf("Enter number n: ");
scanf("%d", &n);
printf("Odd numbers from 1 to %d is: ", n);
while(i <= n){
if(i % 2 == 1)
printf("%d ", i);
i++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 7: Displaying primes from 1 to n with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
bool isPrimes(int n)
{
if (n < 2){
return false;
}
if (n == 2){
return true;
}
if (n % 2 == 0){
return false;
}
for (int i = 3; i < (n - 1); i += 2){
if (n % i == 0){
return false;
}
}
return true;
}
int main() {
int n, i = 1;
cout<<"Enter number n: ";
cin>>n;
cout<<"Primes from 1 to "<< n<<" is: \n";
while(i <= n){
if(isPrimes(i))
cout<<i<<" ";
i++;
}
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
bool isPrimes(int n)
{
if (n < 2){
return false;
}
if (n == 2){
return true;
}
if (n % 2 == 0){
return false;
}
for (int i = 3; i < (n - 1); i += 2){
if (n % i == 0){
return false;
}
}
return true;
}
int main(void) {
int n, i = 1;
printf("Enter number n: ");
scanf("%d", &n);
printf("Primes from 1 to %d is: ", n);
while(i <= n){
if(isPrimes(i))
printf("%d ", i);
i++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 8: Displaying even numbers in array with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
int i = 0, j = 0;
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
cout<<"Elements of array: ";
while(i<9){
cout<<arr[i]<<" ";
i++;
}
cout<<"\nEven numbers in array: ";
while(j<9){
if(arr[j] % 2 == 0)
cout<<arr[j]<<" ";
j++;
}
cout<<"\n\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
int main(void) {
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
int i = 0, j = 0;
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
printf("Elements of array: ");
while(i<9){
printf("%d ",arr[i]);
i++;
}
printf("\nEven numbers in array: ");
while(j<9){
if(arr[j] % 2 == 0)
printf("%d ",arr[j]);
j++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 9: Displaying odd numbers in array with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
int i = 0, j = 0;
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
cout<<"Elements of array: ";
while(i<9){
cout<<arr[i]<<" ";
i++;
}
cout<<"\nOdd numbers in array: ";
while(j<9){
if(arr[j] % 2 == 1)
cout<<arr[j]<<" ";
j++;
}
cout<<"\n\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
int main(void) {
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
int i = 0, j = 0;
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
printf("Elements of array: ");
while(i<9){
printf("%d ",arr[i]);
i++;
}
printf("\nOdd numbers in array: ");
while(j<9){
if(arr[j] % 2 == 1)
printf("%d ",arr[j]);
j++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 10: Displaying primes numbers in array with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
bool isPrimes(int n)
{
if (n < 2){
return false;
}
if (n == 2){
return true;
}
if (n % 2 == 0){
return false;
}
for (int i = 3; i < (n - 1); i += 2){
if (n % i == 0){
return false;
}
}
return true;
}
int main() {
int arr[]={1, 5, 9, 7, 11};
int i = 0, j = 0;
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
cout<<"Elements of array: ";
while(i<5){
cout<<arr[i]<<" ";
i++;
}
cout<<"\nPrimes in array: ";
while(j<5){
if(isPrimes(arr[j]))
cout<<arr[j]<<" ";
j++;
}
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
bool isPrimes(int n)
{
if (n < 2){
return false;
}
if (n == 2){
return true;
}
if (n % 2 == 0){
return false;
}
for (int i = 3; i < (n - 1); i += 2){
if (n % i == 0){
return false;
}
}
return true;
}
int main(void) {
int arr[]={1, 5, 9, 7, 11};
int i = 0, j = 0;
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
printf("Elements of array: ");
while(i<5){
printf("%d ",arr[i]);
i++;
}
printf("\nPrimes in array: ");
while(j<5){
if(isPrimes(arr[j]))
printf("%d ",arr[j]);
j++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 11: Find the sum of elements in array with while loop C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int sum = 0, i = 0, j = 0;
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
cout<<"Elements of array: ";
while(i<9){
cout<<arr[i]<<" ";
i++;
}
while(j<9){
sum += arr[j];
j++;
}
cout<<"\nSum of elements in array: "<<sum;
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
int main(void) {
int sum = 0, i = 0, j = 0;
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
printf("Elements of array: ");
while(i<9){
printf("%d ",arr[i]);
i++;
}
while(j<9){
sum += arr[j];
j++;
}
printf("\nSum of elements in array: %d",sum);
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 12: Find the sum of even elements in array with while loop C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int sum = 0, i = 0, j = 0;;
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
cout<<"Elements of array: ";
while(i<9){
cout<<arr[i]<<" ";
i++;
}
while(j<9){
if(arr[j] % 2 == 0) sum += arr[j];
j++;
}
cout<<"\nSum of even elements in array: "<<sum;
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
int main(void) {
int sum = 0, i = 0, j = 0;
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
printf("Elements of array: ");
while(i<9){
printf("%d ",arr[i]);
i++;
}
while(j<9){
if(arr[j] % 2 == 0) sum += arr[j];
j++;
}
printf("\nSum of even elements in array: %d",sum);
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 13: Find the sum of odd elements in array with while loop C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int sum = 0, i = 0, j = 0;;
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
cout<<"Elements of array: ";
while(i<9){
cout<<arr[i]<<" ";
i++;
}
while(j<9){
if(arr[j] % 2 == 1) sum += arr[j];
j++;
}
cout<<"\nSum of odd elements in array: "<<sum;
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
int main(void) {
int sum = 0, i = 0, j = 0;
int arr[]={1, 5, 9, 7, 11, 2, 10, 6, 7};
/* We have set the value of variable i
* to 0 as the array index starts with 0
* which means the first element of array
* starts with zero index.
*/
printf("Elements of array: ");
while(i<9){
printf("%d ",arr[i]);
i++;
}
while(j<9){
if(arr[j] % 2 == 1) sum += arr[j];
j++;
}
printf("\nSum of odd elements in array: %d",sum);
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 14: Dislaying the multiplication table with while loop C / C++
C++ programming:
#include <iostream>
using namespace std;
int main() {
int n, i = 1;
cout<<"Enter number n: ";
cin>>n;
while(i<= 9){
cout<<n<<" x " <<i<<" = "<<n*i<<"\n";
i++;
}
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
#include <stdbool.h>
int main(void) {
int n, i = 0;
printf("Enter number n: ");
scanf("%d", &n);
while(i<= 9){
printf("%d x %d = %d\n",n,i,n*i);
i++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 15: Import and export elements in an array with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
int main()
{
int n, i = 0, j = 0;
cout<<"Enter the number of elements in the array: ";
cin>>n;
int numbers[n];
while(i < n){
cout << "Enter elements, i = : ";
cin >> numbers[i];
i++;
}
cout<<"\nElements in array: ";
while (j < n){
cout << numbers[j] << " ";
j++;
}
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
int main(void) {
int n, i = 0, j = 0;
printf("Enter the number of elements in the array: ");
scanf("%d", &n);
int numbers[n];
while (i < n){
printf("Enter elements, i = : ");
scanf("%d",&numbers[i]);
i++;
}
printf("\nElements in array: ");
while (j < n){
printf("%d ",numbers[j]);
j++;
}
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 16: Sort array ascending with while loop in C / C++
C++ programming:
#include <iostream>
using namespace std;
void sort_numbers_ascending(int number[], int count)
{
int temp, i, j, k;
for (j = 0; j < count; ++j)
{
for (k = j + 1; k < count; ++k)
{
if (number[j] > number[k])
{
temp = number[j];
number[j] = number[k];
number[k] = temp;
}
}
}
cout<<"\n\nArray after sorting: ";
for (i = 0; i < count; ++i)
cout<<" "<< number[i];
}
int main()
{
int n, i = 0, j = 0, k = 0;
int sum = 0;
cout<<"Enter the number of elements in the array: ";
cin>>n;
int numbers[n];
while(i < n){
cout << "Enter elements, i = : ";
cin >> numbers[i];
i++;
}
cout<<"\nElements in array: ";
while (j < n){
cout << numbers[j] << " ";
j++;
}
sort_numbers_ascending(numbers,n);
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
void sort_numbers_ascending(int number[], int count)
{
int temp, i, j, k;
for (j = 0; j < count; ++j)
{
for (k = j + 1; k < count; ++k)
{
if (number[j] > number[k])
{
temp = number[j];
number[j] = number[k];
number[k] = temp;
}
}
}
printf("\n\nArray after sorting: ");
for (i = 0; i < count; ++i)
printf("%d ",number[i]);
}
int main(void) {
int n, i = 0, j = 0, k = 0;
int sum = 0;
printf("Enter the number of elements in the array: ");
scanf("%d", &n);
int numbers[n];
while (i < n){
printf("Enter elements, i = : ");
scanf("%d",&numbers[i]);
i++;
}
printf("\nElements in array: ");
while (j < n){
printf("%d ",numbers[j]);
j++;
}
sort_numbers_ascending(numbers,n);
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
Example 17: Sort array descending with while loop in C/C++
C++ programming:
#include <iostream>
using namespace std;
void sort_numbers_descending(int number[], int count)
{
int temp, i, j, k;
for (j = 0; j < count; ++j)
{
for (k = j + 1; k < count; ++k)
{
if (number[j] < number[k])
{
temp = number[j];
number[j] = number[k];
number[k] = temp;
}
}
}
cout<<"\n\nArray after sorting: ";
for (i = 0; i < count; ++i)
cout<<" "<< number[i];
}
int main()
{
int n, i = 0, j = 0, k = 0;
int sum = 0;
cout<<"Enter the number of elements in the array: ";
cin>>n;
int numbers[n];
while(i < n){
cout << "Enter elements, i = : ";
cin >> numbers[i];
i++;
}
cout<<"\nElements in array: ";
while (j < n){
cout << numbers[j] << " ";
j++;
}
sort_numbers_descending(numbers,n);
cout<<"\n-------------------------------\n";
cout<<"This program is posted at learnnc.com";
return 0;
}C programming:
#include <stdio.h>
void sort_numbers_descending(int number[], int count)
{
int temp, i, j, k;
for (j = 0; j < count; ++j)
{
for (k = j + 1; k < count; ++k)
{
if (number[j] < number[k])
{
temp = number[j];
number[j] = number[k];
number[k] = temp;
}
}
}
printf("\n\nArray after sorting: ");
for (i = 0; i < count; ++i)
printf("%d ",number[i]);
}
int main(void) {
int n, i = 0, j = 0, k = 0;
int sum = 0;
printf("Enter the number of elements in the array: ");
scanf("%d", &n);
int numbers[n];
while (i < n){
printf("Enter elements, i = : ");
scanf("%d",&numbers[i]);
i++;
}
printf("\nElements in array: ");
while (j < n){
printf("%d ",numbers[j]);
j++;
}
sort_numbers_descending(numbers,n);
printf("\n-------------------------------\n");
printf("This program is posted at learnnc.com");
return 0;
}Output:
