What is the difference between if(CONST==variable) or if(variable==CONST)?

Question

Is there a difference in the order of the comparison operator?

#define CONST_VALUE 5

int variable;

...

if ( variable == CONST_VALUE )   // Method 1
...

O         


        

Answer 1

The first variant

if (variable == CONST_VALUE) 

is better, because it is more readable. It follows the convention (also used in mathematics) that the value that changes most comes first.

The second variant

if (CONST_VALUE == variable)

is used by some people to prevent a mixup of equality checking with the assignment

if (CONST_VALUE = variable)

There are better ways to achieve that, for example enabling and taking heed of compiler warnings.