使用Arraylist查找给定的Integer是否在Array中包含（）

Question

Having problem to check if the given input is in Array or not. Below is just the sample code I wrote. For some reason no matter what I input it outputs "not Okay" even if the number is in array. Any Suggestion or help will be appreciated.

public static void main (String[] args) {
    Scanner input = new Scanner(System.in);
    int array [] = new int[10];
    System.out.println("Please enter the 10 positive integers for BST:"); 
    for (int i = 0 ; i < array.length; i++ ) {
        array[i] = input.nextInt();
    }
    System.out.println("Enter node to delete");
    if (Arrays.asList(array).contains(input.nextInt())){                
        System.out.println("ok");
    } else
        System.out.println("not Okay");
}

Answer 1

Arrays.asList(array) will convert the int[] array into a List<int[]> , then List<int[]>#contains will try to search an Integer . As noted, it will never find it.

Ways to solve this:

• Change int[] to Integer[] .

• Create a method that receives an int and search the element in the array.

(Code won't be shown in the answer since the question looks like a homework exercise).

Answer 2

You can use Arrays.binarySearch() . It returns the index of the key, if it is contained in the array; otherwise, (-(insertion point) - 1). You must use sort() method before:

Arrays.sort(array);
if (Arrays.binarySearch(array, input.nextInt()>=0)