How will you print numbers from 1 to 100 without using loop in C?

You can print numbers from 1 to 100 without using traditional loops by employing alternative control structures like recursive functions and goto statements. These methods achieve the same repetitive behavior through different mechanisms.

Method 1: Using Recursion

Recursion allows a function to call itself repeatedly until a base condition is met. We can use this property to print numbers sequentially without explicit loops −

#include <stdio.h>

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

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

The output of the above code is −

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

Method 2: Using goto Statement

The goto statement provides unconditional jumps to labeled statements, allowing us to create loop-like behavior without actual loop constructs −

#include <stdio.h>

int main() {
    int i = 1;

    start:
        if (i <= 100) {
            printf("%d ", i);
            i++;
            goto start;
        }

    printf("
");
    return 0;
}

The output of the above code is −

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100

Comparison

Conclusion

Both recursion and goto statements can replace traditional loops for printing sequential numbers. While recursion offers cleaner code, goto statements are more memory-efficient for large ranges.