CODEWITHSUNDEEP
javaarraysinteger
user1729448
user1729448

Reputation: 149

Checking if an array contains certain integers

I am making an Array that is 10 integers long, so that each place 0-9 contains a different integer 0-9.

I am having trouble figuring out how to check if the array already contains a certain number, and if so, regenerating a new one.

So far I have:

for (int i = 0; i < perm.length; i++)
{
    int num = (int) (Math.random() * 9); 
    int []

    perm[i] = num;   
}

Upvotes: 0

Views: 50844

Answers (3)

Mjachowdhury
Mjachowdhury

Reputation: 81

Adding both string and integer to check is exist or not.

public class existOrNotInArray {

public static void elementExistOrNot() {
    // To Check Character exist or not
    String array[] = { "AB", "CD", "EF" };

    ArrayList arrayList = new ArrayList<>();

    String stringToCheck = "AB";

    for (int i = 0; i < array.length; i++) {
        arrayList.add(array[i]);
    }

    System.out.println("Character exist : " + arrayList.contains(stringToCheck));

    // To Check number exit or not
    int arrayNum[] = { 1, 2, 3, 4 }; // integer array

    int numberToCheck = 5;

    for (int i = 0; i < arrayNum.length; i++) {
        arrayList.add(arrayNum[i]);
    }
    System.out.println("Number exist :" + arrayList.contains(numberToCheck));
}

public static void main(String[] args) {
    elementExistOrNot();
}
}

Upvotes: 0

Samitha Chathuranga
Samitha Chathuranga

Reputation: 1749

here is a complete answer

int[] array = {3,9, 6, 5, 5, 5, 9, 10, 6, 9,9};

    SortedSet<Integer> s = new TreeSet();
    int numberToCheck=61;
    for (int i = 0; i < array.length; i++) {
        s.add(array[i]);
    }

    System.out.println("Number contains:"+!(s.add(numberToCheck)));


    System.out.println("Sorted list:");
    System.out.print(s);

Upvotes: 0

Nikolay Kuznetsov
Nikolay Kuznetsov

Reputation: 9579

Arrays.asList(perm).contains(num)

from How can I test if an array contains a certain value?

for (int i = 0; i < perm.length; i++)

this is not enough to loop like this, if collision happens some slots would have been not initalized.

Overall, for this task you better initialize array with values in order and then shuffle it by using random permutation indexes

Upvotes: 4

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