Thread: How does having a string with numbers affect a file?

My assignment basically consists of reading from a .txt file and displaying information depending on what the user inputs. One way to look up information is with an ID that starts with N, and is followed by 3 integers. I am aware of the fact that, if I put numbers in a string, they are not really integers (right?). My question is: If I use strings to ask for the ID that the user inputs, will it correctly search for it in the text file?

Numbers can be converted to a string, sure. I believe there is a FAQ on it:
FAQ > Convert an int to a string (char array) (C) - Cprogramming.com

However since the ID is going to be a string anyway, you may want to think about reading the numbers from the user as a string too. This way making the ID number you will search the file with is a much simpler operation, it is just pasting two strings together.

Code:

C:\Users\jk\Desktop>more sandbox.c
#include <stdio.h>
#include <string.h>
int main(void) {
   char actual_id[100] = "N";
   char input[20];
   printf("Enter ID Number (omit N): ");
   scanf("%19s", input);
   strncat(actual_id, input, 19);
   printf("The ID you entered is %s\n", actual_id);
   return 0;
}

C:\Users\jk\Desktop>gcc -ansi sandbox.c

C:\Users\jk\Desktop>a.exe
Enter ID Number (omit N): 123
The ID you entered is N123

Then you can search with that actual_id string, or check it if there are more requirements than what you stated here.

Originally Posted by Patricio Ramos

if I put numbers in a string, they are not really integers (right?).[/code]

Right. But how would you "put numbers in a string"?
Do remember how the char type is defined though.

Originally Posted by Patricio Ramos

My question is: If I use strings to ask for the ID that the user inputs, will it correctly search for it in the text file?

As long as the user input is a stored in a string then the answer is yes.
If you choose to store the user input in an integer, then you will need to do a proper conversion to compare.

That answers my question. Thanks!