Arrays.asList returns false

Question

I just wanna check if my String[] array contains "n" or "s".

String[] coordinatesExample = {"57.8136°s", "28.3496°e"};

private void isContains(String[] coordinates) {

    boolean contains = Arrays.asList(coordinates).contains("s");
        if (contains) {
            System.out.println("It works!");
        }else {
            System.out.println("RAKAMAKAFO");
        }

So I expected: "It works!", but in fact: "RAKAMAKAFO"

What I did wrong?

`"57.8136°s"`contains `"s"`, `{"57.8136°s", "28.3496°e"}` doesn't — jhamon, Feb 18 '20 at 15:17
.contains() on ArrayList will return true if entire element exist. You are checking only "s". — kann, Feb 18 '20 at 15:24
Does this answer your question? [Check if multiple strings exist in another string](https://stackoverflow.com/questions/3389574/check-if-multiple-strings-exist-in-another-string) — Bharat, Feb 18 '20 at 17:43

falknis · Accepted Answer · 2020-02-18T15:54:13.473

Your current solution only works if you have a String Array like this:

String[] coordinatesExample = {"57.8136°s", "28.3496°e", "s"};

Try this if you want to check if any String from your Array contains "n" or "s".

private static void isContains(String[] coordinates) {
    boolean contains = Arrays.stream(coordinates)
            .anyMatch(coordinate -> coordinate.contains("s") || coordinate.contains("n"));
    if (contains) {
        System.out.println("It works!");
    } else {
        System.out.println("RAKAMAKAFO");
    }
}

score 0 · Answer 2 · answered Feb 18 '20 at 15:19

0

When you do Arrays.asList(coordinates) you get the list containing two items: 57.8136°s and 28.3496°e. So using .contains("s") you test if any of your items is "s" which is obviously not the case.

answered Feb 18 '20 at 15:19

Alexey R.

8,057
2
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Apologize.Obviously I didn't know how it's work.Thanks – KennyWood Feb 18 '20 at 20:22

score 0 · Answer 3 · edited Jun 20 '20 at 09:12

Contains only checks to see if the list contains one of the elements which s is not one.

From the JavaDoc for the List interface

boolean contains(Object o)

Returns true if this list contains the specified element. More formally, returns true if and only if this list contains at least one element e such that Objects.equals(o, e).

If you did the following, it would return print It works! because the first string in the list contained an s

private static void isContains(String[] coordinates) {

    boolean contains = Arrays.asList(coordinates).get(0).contains("s");
        if (contains) {
            System.out.println("It works!");
        }else {
            System.out.println("RAKAMAKAFO");
        }
    }
}

Thanks, now I know another one method and solution <3 – KennyWood Feb 18 '20 at 20:20 — KennyWood, Feb 18 '20 at 20:20

Arrays.asList returns false

3 Answers3