"&&" and "and" operator in C
I am trying to calculate the Greatest Common Denominator of two integers.
C Code:
#include <stdio.h>
int gcd(int x, int y);
int main()
{
int m,n,temp;
printf("Enter two integers: \n");
scanf("%d%d",&m,&n);
printf("GCD of %d & %d is = %d",m,n,gcd(m,n));
return 0;
}
int gcd(int x, int y)
{
int i,j,temp1,temp2;
for(i =1; i <= (x<y ? x:y); i++)
{
temp1 = x%i;
temp2 = y%i;
if(temp1 ==0 and temp2 == 0)
j = i;
}
return j;
}
In the if statement, note the logical operator. It is and
not &&
(by mistake). The code works without any warning or error.
Is there an and
operator in C? I am using orwellDev-C++ 5.4.2 (in c99 mode).
Solution 1:
&&
and and
are alternate tokens and are functionally same, from section 2.6 Alternative tokens from the C++ draft standard:
Alternative Primary
and &&
Is one of the entries in the Table 2 - Alternative tokens and it says in subsection 2:
In all respects of the language, each alternative token behaves the same, respectively, as its primary token, except for its spelling. The set of alternative tokens is defined in Table 2.
As Potatoswatter points out, using and
will most likely confuse most people, so it is probably better to stick with &&
.
Important to note that in Visual Studio
is not complaint in C++ and apparently does not plan to be.
Edit
I am adding a C specific answer since this was originally an answer to a C++ question but was merged I am adding the relevant quote from the C99 draft standard which is section 7.9 Alternative spellings <iso646.h>
paragraph 1 says:
The header defines the following eleven macros (on the left) that expand to the corresponding tokens (on the right):
and includes this line as well as several others:
and &&
We can also find a good reference here.
Update
Looking at your latest code update, I am not sure that you are really compiling in C mode, the release notes for OrwellDev 5.4.2 say it is using GCC 4.7.2. I can not get this to build in either gcc-4.7
nor gcc-4.8
using -x c
to put into C language mode, see the live code here. Although if you comment the gcc
line and use g++
it builds ok. It also builds ok under gcc
if you uncomment #include <iso646.h>
Solution 2:
Check out the page here iso646.h
This header defines 11 macro's that are the text equivalents of some common operators.
and
is one of the defines.
Note that I can only test this for a C++ compiler so I'm not certain if you can use this with a strict C compiler.
EDIT I've just tested it with a C compiler here and it does work.