I wrote program that can print number according to user input How to fix length of user input.I want to fix length of user input. I want to write program where user can print only any four numbers. How to fix length of user input ?
Code:#include<stdio.h> int main (void) { int i; printf("user input"); scanf ("%d",&i); printf ("Number's %d \n", i); return 0; }
If you want to stick to using standard I/O facilities, then you cannot control what the user enters, but you can check whether what they entered conforms to your requirements, and if it doesn't, you can reject their input and request for new input that conforms to your requirements. This can be placed into a loop.
Look up a C++ Reference and learn How To Ask Questions The Smart WayOriginally Posted by Bjarne Stroustrup (2000-10-14)
isdigit
if statements
loops // as suggested
for a number how big the number vs more then one set of number(s) for input?
ie. 9 is one digit number whereas 10 is a two digit number, and 100 is a three digit number. etc. so the length of input to check against would depend on what input you are seeking, just check to make sure it matches if not, discard their first reply and ask again. ie loop
or go sloppy, and just use the first chunk of input (amount you actually want) for your operation on it, and the rest just gets left out no matter what. check that if it is invalid loop around and have them try it again.
Code:while (not what you want) { ask question, get input } do more stuff ....
Last edited by userxbw; 10-09-2017 at 03:51 PM.
fgets() and sscanf() are a pretty standard approach as well. Use a format like "%4d%c", and if you get two conversions and the character is an \n, then the input is good.
