将输入与两个字符进行比较，产生奇怪的警告

Question

I am trying to compare an input to two different characters and execute the if condition if either of the conditions are met.

My code so far is:

if(i == 'Y'||'y') {
        //code here
}

but the GCC compiler spits out the warning:

warning: use of logical '||' with constant operand
      [-Wconstant-logical-operand]

why is this happening?

Answer 1

What you meant to say was:

  if(i == 'Y'|| i == 'y')

The compiler is telling you exactly what you needed to know!

Answer 2

If you don't want to repeat the conditional (ie for a long list of options) you can use:

if (strchr("Yy", i) != NULL) {
    ....
}

You need to #include <string.h>