cant find which loop to use ><

#include <stdio.h>
int main ()
{

char string1[27] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
char string2[27] = "abcdefghijklmnopqrstuvwxyz";
int value = 0;

printf("To print the alphabet in\n");
printf("Uppercase enter 0\n");
printf("lowercase enter 1\n");
scanf("%i",&value);

while ((value != 0) && value != 1)
{
printf("Invalid entry please enter only 0 or 1\n");
scanf("%i\n",&value);
}

if (value == 0)
{
printf("%s", string1);
}
else if (value == 1)
{
printf("%s", string2);
}
return 0;

}

this is what i got which works to an extent but for some reason after entering e.g 9 then 0 it needs me to enter another int so for some reason which i cant see

What you are trying to do is more of a logical issue. You are attempting to catch input when it is a 0 or a 1. Your logic 'Looks' like good logic, but really it isn't.

Let me explain what you are saying:

if (value != 0||1)

What this means is this, If the variable value is not equal to undefined then do this.

What you mean is this,

If the variable value is not equal to 0 AND the variable value is not equal to 1 then do this.

Simply put you are confusing the || or comparitor. You need to have 2 tests, but you only have one.

As to the Loop, here is an example of what I think you wanted.

#include

"stdafx.h"

int _tmain(int argc, _TCHAR* argv[])

{

//Create two string arrays, one upper, one lower.

char string1[27] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

char string2[27] = "abcdefghijklmnopqrstuvwxyz";

//Create an integer to catch the user input.

int value = 0;

// create a loop to prompt the user.

While (value == 0)

{

printf(To print the alphabet in\n");

printf("uppercase enter 1\n");

printf("lowercase enter 2\n");

scanf("%i",&value);

} //end of while loop

// Test the input, if the input is not 1 and input is not 2,

if ((value != 1)&&( value != 2))

{

printf("Invalid entry please enter only 0 or 1");

}

// If the input is a one, send the Upper Case String.

else if (value == 1)

{

printf("%s",string1);

}

// If the input is two, send the Lower Case String.

else if (value == 2)

{

printf("%s",string2);

}

//exit the program.

return 0;

}