CODEWITHSUNDEEP
cexpression
samprat
samprat

Reputation: 2214

problem in boolean expression with if statement

I need some confirmation. I always get correct o/p but someone told me following expression will not work

Thanks in advance.

#define a 11

#define b 12

#define c 13     
    // I want if array[i] has values of any of these  then do something
    if( array[i] ==  (a) ||(b) ||( c))    
   // some function    
  else    
  printf("no match");

Upvotes: 0

Views: 425

Answers (4)

Seb Holzapfel
Seb Holzapfel

Reputation: 3873

What you're doing is or'in the result of the boolean evaluation array[i]==a directly towards b, c.

In other words, ( (array[i] == a) || (b) || (c) ) is effectively what you're doing - probably not what you intended!

You will need to evaluate the boolean expressions separately:

(array[i] == a) || (array[i] == b) ...

Upvotes: 2

Carl Norum
Carl Norum

Reputation: 225282

"Someone" is correct. You need to use:

if ((array[i] == a) || (array[i] == b) || (array[i] == c))

Your program does not always produce correct output. Try it with any i not equal to 11, 12, or 13.

Upvotes: 0

Sam Holloway
Sam Holloway

Reputation: 2019

Replace your code with this:

if( array[i] == a || array[i] == b || array[i] == c)

Each part of the boolean condition must be a complete expression. While what you wrote is valid C code, it doesn't achieve what you want: you need to make an array element comparison in every part.

Upvotes: 1

rtheunissen
rtheunissen

Reputation: 7435

 if (array[i] ==  a || array[i] == b || array[i] == c){
       ... 
   }

I do wish sometimes that you could say if (array[i] == [a, b, c]) or something to that effect.

Upvotes: 2

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