Question

#include<stdio.h>

main()
{
      unsigned  x=1;
      signed char y=-1;
      clrscr();
      if(x>y)
       printf("x>y");
      else
     printf("x<=y");
}

A signed character has an increased value from -128 to 127. So the expected out put should have been ‘x>y’, but it isn’t. The compiler gives the output – “x<=y”. Can you explain why?

Answer 1

In the comparison the signed char gets converted to an unsigned int and thus looks like a really big value. I would expect the compiler to warn you – i.e. something in the lines “comparing signed and unsigned stuff is confusing”.

This conversion is mandated under “Relational operators”:

If both of the operands have arithmetic type, the usual
arithmetic conversions are performed.