Problem with inputing only a number from 1 to 1000

Question

Working on Ubuntu

I have a problem with my code and i dont know how to fix. Maybe there is a function that will help me with that.

I want to input a string and then my program need to check if it is a number from 1 to 1000. If there is a letter or a symbol

Here is my code:

    char tab[200]="";
    int i;
    scanf("%199[^\n]s",tab);
    for(i=0;i<200;i++)
    {
        if(tab[i] >= 'A' && tab[i]<='Z')
        {
            printf("Big letters\n");
        }
        else if(tab[i] >= 'a' && tab[i]<='z')
        {
            printf("Small letters\n");
        }
    }
    if(strlen(tab) == 4 && tab[3] > 0 && tab[2] > 0 && tab[1] > 0 && tab[0] > 1)
    {
    printf("Bigger then 1k\n");
    }
    else if(strlen(tab) > 4)
    {
        printf("Longer then 4 chars\n");
    }

It's not working properly and it also doesnt include symbols...

I've found code like this but im not sure how to make my number less then 1001

    char input[MAXINPUT] = "";
    int length,i; 
    int number;



    printf(" id: \n");
    fgets(input, MAXINPUT, stdin); 
    number = atoi(input);
    length = strlen (input);
    for (i=0;i<length; i++)
        if (!isdigit(input[i]))
        {
            printf ("Entered input is not a number\n");
            exit(1);
        } else if (number < 1001)
    printf ("Given input is a number\n");

Not sure if i am using fgets properly here.

Before u will send me to here , please read my question

"It's not working properly" lacks information. Post input used, output seen and output expected. — chux - Reinstate Monica, Aug 08 '19 at 14:51
Recommend `printf ("Entered input is not a number. character code: %d\n", input[i]);` for informative error output. I suspect you will get a `10` as `'\n'` is not a digit. — chux - Reinstate Monica, Aug 08 '19 at 14:53

score 0 · Answer 1 · answered Aug 08 '19 at 11:19

Use This.. Maybe This Help. You can Modify it on your Choice.

#include<string.h>              // header file for strlen()
void method()
{
  char tab[200]="";
  int i;
  scanf("%199[^\n]s",tab);
    for(i=0;i<strlen(tab);i++)   // Loops only to the lenght of total vlaues in array
    {
    if(tab[i] >= 65 && tab[i]<=90)          // Ascii Value of Capital Ltrs
    {
        printf("Big letter\n");
    }
    else if(tab[i] >= 97 && tab[i]<=122)      // Ascii Value of Small Ltrs
    {
        printf("Small letter\n");
    }
     else if(tab[i] >= 48 && tab[i]<=57)    // Ascii Value of Numbers
    {
        printf("Number\n");
    }else          // of else other numebrs are all Symbols but can be 
    {
         printf("Symbols\n");
    }

}

}

Without checking the return value of `scanf("%199[^\n]s",tab);`, code will fail to function as desired, especially when only a `'\n'` is read. — chux - Reinstate Monica, Aug 08 '19 at 14:49

score 0 · Answer 2 · answered Aug 08 '19 at 11:38

Please note that you're compareing characters with integers (numbers). The character '1' in ascii is 49, as an example, while you have been using the numeric value 1 in the comaprisons. Test to add single quotation marks similar to those around your letter comparisons and see if you don't get a different result.

Best regards Esbjörn

Problem with inputing only a number from 1 to 1000

2 Answers2