Multiple return statement in java [closed]

Question

private void test() {           
        // Nested if block 
        if (true) { // If condition is true
            if (true) { // If condition is true
                if (true) { // If condition is true
                    if (true) { // If condition is true
                         // statement
                    }
                }
            }
        }

        // Above block breaking in below way
        // Breaking nested if in multiple with return statement
        if (false) { // If condition is false
            return;
        }

        if (false) { // If condition is false
            return;
        }

        if (false) { // If condition is false
            return;
        }

        if (false) { // If condition is false
           return;
        }
    }

OOPs suggest multiple return statement is bad idea. But if I used multiple nested if then its look very complex. Please suggest what is best way to use nested if condition

Answer 1

Multiple return statements is not good or bad in itself.
Early return and fail fast principle are not bad ways of coding and yet they rely on multiple return statements.
A single thing matters : the consistence and the code readability.

Your second way uses the "early return" pattern :

if (false) { // If condition is false
    return;
}

if (false) { // If condition is false
    return;
}

if (false) { // If condition is false
    return;
}

if (false) { // If condition is false
   return;
}

Now nothing prevents you from improving this code by removing the duplication : if (...) returns ...;.
Abusing of these can indeed finish to produce a less readable code because too noises and scattered rules.

Your example is really too abstract to provide a specific answer.
So, suppose that multiple of your conditional statements rely on a object of a specific class to be evaluated.

In this case, you could store conditional statements in a List and iterate on it to apply each rule. As soon as one is not valid, you exit.

List<Predicate<MyObject>> predicates = Arrays.asList(MyObject::isValid, 
                                                    (m)-> m.getColor()==BLUE);

And now apply rules :

MyObject myObj = ...;
for (Predicate<MyObject> predicate : predicates) {
    if (!predicate.test(myObj)) {
      return false;
    }
}