Change int to some string

Question

So I tried to get a number(int) from the user and move the number from the integer to the empty string, and than i need to print it like a string. help?

   #include <stdlib.h>
#include <stdio.h>
#include <time.h>
#include <string.h>
#define  CHAR_LENGTH 100
int main()
{
    int num =0,units=0 ,length=0,counter =0,i=0 ;
    char charNumber[CHAR_LENGTH]={0};
    printf("enter some number(positive or negative)\n");
    scanf("%d",&num);
    while (num != 0)
    {
        units =0;
        units = num %10;
        num = num / 10;
        charNumber[i]= (char)units;
        counter++;
        i++;
    }
    printf("%s",charNumber);
    return 0;
}

Agreed, but when another number is entered? It is good practice to insert the terminator anyway. — Weather Vane, Jan 11 '16 at 16:36
What is the expected behavior ? And what do you get ? Give an example of execution scenario fro both expected behavior and for what do you get. — mikedu95, Jan 11 '16 at 16:38
This also prints the number in reverse, and mis-handles negative numbers. — Weather Vane, Jan 11 '16 at 16:40
Just a FIY ... the number, while being typed on the keyboard by the user, is a string to begin with. What you are doing is having the runtime library (`scanf()`) convert that string to an integer, then your program convert the integer back to a string. Maybe, just maybe, you can make use of the original string (from the keyboard) directly :-) — pmg, Jan 11 '16 at 16:40
Possible duplicate of [How to convert an int to string in C](http://stackoverflow.com/questions/8257714/how-to-convert-an-int-to-string-in-c) — Uyghur Lives Matter, Jan 11 '16 at 18:40

score 2 · Answer 1 · edited May 23 '17 at 12:04

2

Do you need to write an algorithm yourself? If not, use itoa function of C standard library (although it's not so standard, but some libraries include it).

You can also use sprintf like this:

int value = 2016;
char my_string[64];

snprintf(my_string, 64, "%d", value);

Check out these links as well:

edited May 23 '17 at 12:04

Community

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answered Jan 11 '16 at 16:34

ForceBru

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@EdHeal, I was just editing my answer to add this :) – ForceBru Jan 11 '16 at 16:37
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Except that itoa is *not* a standard C function. snprintf is a better way in C. – mikedu95 Jan 11 '16 at 16:37
This is a fairly common beginning programming assignment, so there's a reasonable chance that's not an allowed approach. – John Hascall Jan 11 '16 at 16:39

score 1 · Answer 2 · answered Jan 11 '16 at 16:44

1

Three problems:

(1) Negative numbers. if (num < 0) { printf("-"); num = -num; }
(yes, I ignored the obvious corner case)

(2) You print the digits in the backwards order.

(3) You need to add '0', as in charNumber[i]= (char)units + '0'

answered Jan 11 '16 at 16:44

John Hascall

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Change int to some string

2 Answers2