Why would square root of 1 equals 1 returns false in java?

Question

public static boolean checkSquare(int i){
    return IntStream
            .rangeClosed(1, i/2)
            .anyMatch(x -> Math.sqrt(x) == i);
}

When I enter 1 as an user input, it return false. I don't understand why square root of 1 is not equals to 1. Can anyone tell me is my code correct?

Further reading: [Why is the result of 1/3 == 0?](https://stackoverflow.com/questions/4685450/why-is-the-result-of-1-3-0) — LuCio, Oct 10 '18 at 06:34
Do *not* change an existing question to something entirely else, please. — Jongware, Oct 10 '18 at 20:56

score 4 · Answer 1 · answered Oct 10 '18 at 06:30

If your user input is assigned your i variable, it's clear why

IntStream.rangeClosed(1, i/2).anyMatch(x -> Math.sqrt(x) == i);

returns false when i==1, since 1/2 == 0, so IntStream.rangeClosed(1, 0) is an empty stream.

Change your method to:

public static boolean checkSquare(int i){
    return IntStream
            .rangeClosed(1, i)
            .anyMatch(x -> Math.sqrt(x) == i);
}

or, if you really want to keep the optimization of halving the size of the IntStream:

public static boolean checkSquare(int i) {
    return IntStream
            .rangeClosed(1, Math.max(1,i/2))
            .anyMatch(x -> Math.sqrt(x) == i);
}

Now i understand my mistake. Thank you so much for your explanation. — , Oct 10 '18 at 06:43
@SendHelpPls if an answer really solves your question, mark it as answer. — The Scientific Method, Oct 10 '18 at 06:52

Why would square root of 1 equals 1 returns false in java?

1 Answers1