How do I put in while condition that my viariable must be not a character

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Hello;
I am having some little troubles finding out a way to put under my while condition the fact that my variable which is an "int" must be not a character took from an input requested before my while cycle.
While cycle is used to check if the variable wrote in input doesnt match with conditions i need for the algorithm.

What I have tried:

here is an example of code:
#include <stdio.h>

int main(){
int n;
scanf("%d", &n);
while(n<=-1 ){
printf("Incorrect. Write a positive integer.");
scanf("%d", &n);
}

return 0;
}

This is working for numbers, but if in input i write a character like "g" it loopes and i must control+c, blocking it.

Posted 11-Oct-18 0:49am

Member 14015940

Updated 11-Oct-18 1:06am

#realJSOP

v4

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#realJSOP 11-Oct-18 7:07am

This is not a C# question. I changed the tag so it would be correctly categorized.

1 solution

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Richard MacCutchan · Accepted Answer · 2018-10-11T01:07:00

Solution 1

You tagged this C#, but it is clearly C or C++.
However, this is quite a simple problem to resolve with a loop:

C++

int n;
while (scanf("%d", &n) == 0 || n < 0) // if no values captured, or the result is negative
{
    printf("Incorrect. Write a positive integer.");
    fseek(stdin,0,SEEK_END);
}

Posted 11-Oct-18 1:07am

Richard MacCutchan

Updated 11-Oct-18 1:56am

v2

Comments

Member 14015940 11-Oct-18 7:30am

Thank you for the answer, im a very beginner.

With the new condition, if i still put a character it gives me the same problem.

"d
Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. Write a positive integer.Incorrect. "

I dont get why

Richard MacCutchan 11-Oct-18 7:56am

Sorry, I forgot to clear the input buffer after reading a non-number. See my updated solution.

CPallini 11-Oct-18 9:11am

5.