Print 1 to 100 Numbers in C (4 Different Methods)

Printing 1 to 100 number in C using 4 different methods:

Method 1: Using a for loop

#include <stdio.h>

int main() {
    for (int i = 1; i <= 100; i++) {
        printf("%d ", i);
    }
    return 0;
}

Method 2: Using a while loop

#include <stdio.h>

int main() {
    int i = 1;
    while (i <= 100) {
        printf("%d ", i);
        i++;
    }
    return 0;
}

Method 3: Using a do-while loop

#include <stdio.h>

int main() {
    int i = 1;
    do {
        printf("%d ", i);
        i++;
    } while (i <= 100);
    return 0;
}

Method 4: Using recursion

#include <stdio.h>

void printNumbers(int n) {
    if (n <= 100) {
        printf("%d ", n);
        printNumbers(n + 1);
    }
}

int main() {
    printNumbers(1);
    return 0;
}

The first 3 methods are pretty basic. However, method 4 uses recursion to print the numbers from 1 to 100. Recursion is a technique in which a function calls itself to solve a smaller instance of the same problem.

In this method, we have a function called printNumbers that takes an integer parameter n. It checks if n is less than or equal to 100. If it is, it prints the value of n and then calls itself with n+1 as the argument.

The recursion continues until n exceeds 100, at which point the function calls stop and the program terminates.

Here’s a step-by-step explanation of how the recursion works:

1. The printNumbers function is called with an initial value of n as 1.
2. The function checks if n is less than or equal to 100. Since 1 is less than 100, it proceeds to the next step.
3. It prints the value of n (which is 1) using printf.
4. The printNumbers function calls itself with n+1 as the argument. This creates a new instance of the function with n set to 2.
5. The new instance of the function repeats the process from step 2 with n as 2. It prints 2 and calls itself with n as 3.
6. This recursion continues until n reaches 100. Each function instance prints its value and calls the next instance with an incremented value of n.
7. Once the value of n becomes greater than 100, the recursion stops, and the program terminates.

Note These methods will all produce the same output, printing the numbers from 1 to 100 separated by spaces. Choose the one that suits your needs best.