Thread: Finding the first digit in a number....help

Hey guys, just wanted to first off say thanks for all the help in the past.

I was wondering how to go about finding the first digit from a number inputted into an array.

Thank you for any help.

ex.
enter the numbers to use:
9
45
682
120

output:
the numbers are 9 4 6 and 1


Here is what I have, the array goes to a max of 15 for the moment, but I allow the user to input as large an array as they want up to that number. Then the user is to input it's numbers.

Code:

#include <stdio.h>

#define MAX 15
int main()
{

int array[MAX]; /*Array to place numbers in*/
int num;        /*Amount of number to use in game*/
int num1;       /*Number to be inputted for game*/
int i, j, k;


  printf("How many numbers would you like to have?\n");
  scanf("%d", &num);

    for(i = 0; i < num ; i++){  /*Starts loop to input numbers into array*/
      scanf("%d", &num1);
      array[i] = num1;   
      }
       
  printf("\n");
  
    for(k = 0; k < num; k++){  /*Loop prints the array*/
      printf("%d ", array[k]);
      }
       
  return 0;
}

for the moment i have found it on this thread.

Code:

 while (num1 >= 10)
    num1 /= 10;

would there be a better to go about this? Such as turning it to a string?

Such as turning it to a string?

Yes, definitely... well, actually, forget about turning it into an integer. If all you're going to do is find the first digit, you might as well this:

Code:

char mynumber[20];

/*in loop*/
scanf("%s", &mynumber);
array[i] = (int) mynumber[0] - (int) '0');

Obviously this is incomplete but the idea is there; also you'll want to protect against the evils of the scanf("%s") security hole, and look for the first actual digit [skipping '-' if it's there] in the string. "I'll leave that to the reader as an exercise."