C Program to Print numbers from 0 to 10 and 10 to 0 using While loops

C While Loop: Exercise-1 with Solution

Write a C program to print numbers from 0 to 10 and 10 to 0 using two while loops.

Sample Solution:

C Code:

#include <stdio.h>

int main() {
    int i = 0;  // Initialize the loop counter

    // First while loop: Print numbers from 0 to 10
    printf("Numbers from 0 to 10:\n");
    while (i <= 10) {
        printf("%d ", i);  // Print the current value of i
        i++;  // Increment the loop counter
    }

    printf("\n");  // Move to the next line for better formatting

    i = 10;  // Reset the loop counter to 10

    // Second while loop: Print numbers from 10 to 0
    printf("\nNumbers from 10 to 0:\n");
	while (i >= 0) {
        printf("%d ", i);  // Print the current value of i
        i--;  // Decrement the loop counter
    }

    return 0;  // Indicate successful program execution
}

Sample Output:

Numbers from 0 to 10:
0 1 2 3 4 5 6 7 8 9 10

Numbers from 10 to 0:
10 9 8 7 6 5 4 3 2 1 0

Explanation:

Here are key parts of the above code step by step:

• #include <stdio.h>: This line includes the standard input-output library, allowing functions like "printf()" and "scanf()".
• int main() {: This marks the beginning of the "main()" function, the entry point of the C program.
• int i = 0;: Declares an integer variable 'i' and initializes it to 0. This variable will be used as a loop counter.
• while (i <= 10) {: Starts the first while loop, which runs while the value of 'i' is less than or equal to 10.
• printf("%d ", i);: Prints the current value of 'i' followed by a space.
• i++;: Increments the value of 'i' by 1 in each iteration of the loop.
• }: Closes the first while loop.
• printf("\n");: Prints a newline character to move to the next line for better formatting.
• i = 10;: Resets the value of 'i' to 10 for the second while loop.
• while (i >= 0) {: Starts the second while loop, which runs while the value of 'i' is greater than or equal to 0.
• printf("%d ", i);: Prints the current value of 'i' followed by a space.
• i--;: Decrements the value of 'i' by 1 in each iteration of the loop.
• }: Closes the second while loop.
• return 0;: Indicates that the program executed successfully and returns 0 to the operating system.
• }: Closes the main function.

Flowchart:

C Programming Code Editor:

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