Question

This is a snippet of Java code:

static boolean a; // gets false
static boolean b; 
static boolean c;

    public void printA(){

         boolean bool = (a = true) || (b = true) && (c = true);    
         System.out.print(a + ", " + b + ", " + c);     
    }

It does not compile, what is the prob? Error: multiple markers on this line; syntax error on the line of ‘bool’ variable.
I expect it to print true, false, true.
Although according to my tutorial books it prints true, false, false.

I understand it performs short-circuiting but in case of && both sides needs to be evaluated. That is not a homework, I am learning Java.
Cheers

Answer 1

(a = true) || (b = true) && (c = true);

is equivalent to: –

(a = true) || ((b = true) && (c = true));

Since (a = true) is evaluated to true, hence the 2nd expression is not evaluated, since you are using short-circuit operator (||) there.

And hence the last two assignment does not happen. And the values of b and c remain false.

Note: – Short-circuit operators – && and ||, does not evaluate further if a certain result can be obtained by previous evaluation.

So: –

• a && b will not evaluate b, if a is false.

• a || b will not evaluate b, if a is true.