CODEWITHSUNDEEP
java
attofi
attofi

Reputation: 288

OR operator - which statement is more efficient?

When I use the OR operator, only one expression has to be true. Is the first if statement more efficient because java checks only the first expression? Or does java check both?

public class Test {
    public static void main(String args[]) {

        boolean test = true;

        if (test || calculate()) {
            // do something
        }

        if (calculate() || test) {
            // do something
        }
    }

    public static boolean calculate() {
        // processor-intensive algorithm
    }
}

Upvotes: 0

Views: 132

Answers (3)

Santhosh
Santhosh

Reputation: 8197

Yes , it is . because calculate() is never called , as long as test is true and it is the contract of || statements.

From §15.24,

The conditional-or operator || operator is like | , but evaluates its right-hand operand only if the value of its left-hand operand is false.

Upvotes: 1

Stultuske
Stultuske

Reputation: 9437

There are two or operators:

if ( condition | condition2 ){

Here, it will test the second condition regardless of the outcome of the second condition.

if ( condition || condition2 ){

Here, the second condition will only be checked if the first condition returned false.

The same way of double operators is implemented for the 'and' operators & and &&

Upvotes: 0

Eran
Eran

Reputation: 393856

if (test || calculate())

would never call calculate() when test is true, since || operator is short circuited, so that statement is more efficient when test is true.

Upvotes: 9

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