Question

Sometimes i extract boolean checks into local variables to achief better readability.

What do you think?

Any disadvantages?

Does the compiler a line-in or something if the variable isn’t used anywhere else? I also thought about reducing the scope with an additional block “{}”.

if (person.getAge() > MINIMUM_AGE && person.getTall() > MAXIMUM_SIZE && person.getWeight < MAXIMUM_WEIGHT) {
    // do something
}

---

final boolean isOldEnough = person.getAge() > MINIMUM_AGE;
final boolean isTallEnough = person.getTall() > MAXIMUM_SIZE;
final boolean isNotToHeavy = person.getWeight < MAXIMUM_WEIGHT;

if (isOldEnough && isTallEnough && isNotToHeavy) {
    // do something
}

Answer 1

I do this all the time. The code is much more readable that way. The only reason for not doing this is that it inhibits the runtime from doing shortcut optimisation, although a smart VM might figure that out.