C Tutorial/Data Type/Equality

Comparing the equality operator (==) with the "=" assignment operator.

a b a = b a == b 5 3 a = 3 (true) false 7 0 a = 0 (false) false 0 0 a = 0 (false) true

To test two expressions for equality, use == instead of =

<source lang="cpp">#include <stdio.h> main(){

 int i = 5;
 if(i == 5){
    printf(" ==. \n");
 }
 if(i=4){
    printf("do not use = ");
 }

}</source>

==.
     do not use =