Which loop should I select in Programming?

You should select for loop cause of the following:

  • If you know the exact number of times  or counting number you want to loop iteration.
  • If you want to do multiplication table.
  • If you want to iterate over arrays.
  • If you have single loop condition.
Example:

#include <stdio.h>
int main(int argc, char const *argv[])
{   
    int count = 10; // Exact number of time is known
    for (int i = 0; i < count; ++i)
    {
        printf("%d\n", i);
    }
    return 0;
}

But you should avoid for loop if the variable needs to be updated in for loop.
Which loop should I select in Programming

You should select while loop cause of the following:

  • If you don't know the exact number of times  or counting number you want to loop iteration but you know the condition till the loop will be continued.
  • If you need the variable to be updated.
  • If you need to update  step requires multiple lines of code.
  • If you have a complicated loop condition.
Example:

#include <stdio.h>
int main(int argc, char const *argv[])
{
    int i = 0;
    int j = 5;

    while ( i < 10 && j > 0 )
    {
        printf("%d\n",i * j);

        j = i - j;
       
        i++;
    }
    return 0;
}

You should select do while loop cause of the following:


Expert programmers always suggest to avoid this loop without using do-while loop to do something at least once.