How to ask the user if they wish to input another value in c

This is how i attempted it, how ever when i enter q it just skips a line in command and continues the program.

int main()
{
int a;
char c;
cont(&a);
while(a != 'q' && a != 'Q')
{
while ( ( c = getchar() ) != EOF)
{
    putchar(开发者_运维知识库 r13( c ) );    
 }
}

return 0;
 }

You need to pass the reference of a to cont() -

void cont(int* a)
{ 
    printf("If you do not want to enter a value press q"); 
    scanf("%c", a);
}

and call it like that:

cont(&a);

otherwise, only the the copy of a (that is passed to the function) is changed, not a itself.

If you want to change the value of a in the function, then you need to store the return value somewhere, but you ignored it (e.g. a = cont(a);).
Or, give a reference (e.g. address of) a to the function, so it will be able to change the value of a.