java Cannot resolve method 'contains(int)'

Question

This code block prints "not contains" and i don't know why, can somebody help me ?

private static final int[] YEARS = new int[] {
        1881, 1893, 1900, 1910, 1919, 1923, 1930, 1932, 1934, 1938
};

public static void main(String[] args) {
    int year = 1919;
    System.out.println(YEARS);

    if (Arrays.asList(YEARS).contains(year))
    {
        System.out.println("Contains");
    }
    else {
        System.out.println("Not contains");
    }
    // Write your code here below
}

}

Does this answer your question? [Arrays.asList() not working as it should?](https://stackoverflow.com/questions/1467913/arrays-aslist-not-working-as-it-should) — Chaosfire, Nov 01 '22 at 08:39
Additionally, please fix question title, it has nothing in common with the actual question you are asking. — Chaosfire, Nov 01 '22 at 08:40
there is no method `asList(int... )` (receiving primitive values), only `asList(T...)` and the generic type `T` cannot receive primitives, so it is creating a list with a single object, the whole (int) array itself || you can use `Arrays.binarySearch(int[], int)` if the array is sorted; or use `IntStream.of(YEARS).anyMatch(y -> y==1919)` — user16320675, Nov 01 '22 at 10:17

score 1 · Answer 1 · answered Nov 01 '22 at 08:37

1

that's because you are using int in your arraylist when you should be using Integer

int is a primitive type and doesn't work with Arraylist which requires a non-primitive type

change int to Integer and that code should work

answered Nov 01 '22 at 08:37

Icarus

501
2
16

score 1 · Accepted Answer · answered Nov 01 '22 at 11:40

Arrays.asList(YEARS) will result in a List<int[]>, you will not find a single int in there using the contains(int) method of a List…

You probably expected a List<Integer>, which you can get by

List<Integer> years = Arrays.stream(YEARS).boxed().collect(Collectors.toList());

The resulting List<Integer> can be checked for the presence of a single int using the contains method because it is a list of integers contrary to the list of arrays of integers produced by Arrays.asList(YEARS).

java Cannot resolve method 'contains(int)'

2 Answers2