Finding if given Integer is in Array or not using Arraylist contains ()

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");
}

Luiggi Mendoza · Accepted Answer · 2014-04-30 15:25:30Z

2

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).

answered Apr 30, 2014 at 15:25

Luiggi Mendoza

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1 Comment

user3478869 Over a year ago

Thank you sir. Worked just fine

Jose Pardo · Accepted Answer · 2014-04-30 15:44:57Z

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)

answered Apr 30, 2014 at 15:44

Jose Pardo

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