TO find whether MSB of a unsigned int/char is ZERO or ONE

[martin paul]

Sir please consider the following code.I've tried the following code to print whether the MSB of a int/char is zero or one.
int main ()
{
unsigned char ch;
int i=0;
printf("enter the value\n");
scanf("%d",&ch);
if((ch & 10000000)==1)
printf("msb is one\n");
else
printf("msb is zero\n");
}
To the above code I've given input as 254(which has msb as one)but the output is displaying as msb is zero. Sir could you tell me what is wrong in the above code.Should I use "for loop" .
Thank you.

[horace1]

try changing

if((ch & 10000000)==1)
 

to

if((ch & 10000000)==10000000)
 

i.e. the logical AND of ch and 10000000 will be 10000000 if the MSB of the byte is set otherwise 0

[willakawill]

Sir please consider the following code.I've tried the following code to print whether the MSB of a int/char is zero or one.
int main ()
{
unsigned char ch;
int i=0;
printf("enter the value\n");
scanf("%d",&ch);
if((ch & 10000000)==1)
printf("msb is one\n");
else
printf("msb is zero\n");
}
To the above code I've given input as 254(which has msb as one)but the output is displaying as msb is zero. Sir could you tell me what is wrong in the above code.Should I use "for loop" .
Thank you.

Hi This expression
ch & 10000000
will return 10000000 or 128 decimal, not 1.

Try this
if ((ch / 128) == 1)

[willakawill]

try changing

if((ch & 10000000)==1)
 

to

if((ch & 10000000)==10000000)
 

i.e. the logical AND of ch and 10000000 will be 10000000 if the MSB of the byte is set otherwise 0

This expression:

if((ch & 10000000)==10000000)
 

will not work because '==' is not a bitwise operator. It is not required anyway because we are testing for true or false. Therefore

if(ch & 10000000)
 

is either true or false. If true then MSB is 1