Storing each individual digit from an integer in array-CodePudding

Good day,

I am quite new to c and trying to find a way to store user integer input into an array as individual digits.

For example,

User input: 2736

I would like it to be stored in array

digits[0] = {2} 
digits[1] = {7} 
digits[2] = {3} 
digits[3] = {6}

I have searched many online discussions but many solutions was to use a for loop and it would not be user friendly if the user is trying to enter a large number for example 209377383838.

Does anyone have a solution to store an input, break it down and store individual number into the array? Thanks for the help!

CodePudding user response：

You can store the number from user as string and then convert from ASCII format to decimal and store it in your array:

#include <stdio.h>
#include <string.h>

int main(){
    char input[1001];
    int arr[1000];
    int i;

    // Take the number as string
    printf("Enter the number: ");
    scanf("%s", input);

    // Convert ASCII to decimal
    for (i = 0; i < strlen(input); i  )
    {
        arr[i] = input[i] - '0';
    }

    return 0;
}

CodePudding user response：

You can use sprintf function to put an integer number to a string.

Note1: As the input is a long int, then can't be more than 2,147,483,647.

Note2 : may be interesting to use unsigned long long int, that Contains at least the [0, 18,446,744,073,709,551,615] range. It's specified since the C99 version of the standard.

int main()
{
long int num; 
scanf("%li",&num);

// Convert number to a string
char snum[20];
sprintf(snum,"%ld", num);

printf("Number as string: %s\n", snum);

return 0;
}

[Update]

If the input can be a string type, then you can use the gets function.

#include <stdio.h>
int main()
{
char snum[20];  
gets(snum);
    // this loop is just to show the result.
    for (int i=0;i<strlen(snum);i  ){
        printf("digits[-] = {%c} \n", i,snum[i]);
    }

return 0;
}

[Input] example: 209377383838

[Output]

digits[ 0] = {2} 
digits[ 1] = {0} 
digits[ 2] = {9} 
digits[ 3] = {3} 
digits[ 4] = {7} 
digits[ 5] = {7} 
digits[ 6] = {3} 
digits[ 7] = {8} 
digits[ 8] = {3} 
digits[ 9] = {8} 
digits[10] = {3} 
digits[11] = {8}