Question

How to remove duplicate numbers from array in Java

Answer 1

import java.util.Arrays;
import java.util.LinkedHashSet;

public class MyClass {
    public static void main(String args[]) {
        Integer[] arr = new Integer[] {3, 5, 2, 3, 1, 1, 1, 2, 6, 9, 7, 2};
         
        LinkedHashSet<Integer> lhs = new LinkedHashSet<>(Arrays.asList(arr));
         
        arr = lhs.toArray(new Integer[] {});
         
        System.out.println(Arrays.toString(arr));
    }
}



/*
run:

[3, 5, 2, 1, 6, 9, 7]

*/

 

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Answer 2

import java.util.Arrays;
import java.util.LinkedHashSet;

public class MyClass {
     private static Integer[] remove_duplicates(Integer[] arr) {
 
        LinkedHashSet<Integer> lhs = new LinkedHashSet<>(Arrays.asList(arr));
          
        arr = lhs.toArray(new Integer[] {});
         
        return arr;
    }
    public static void main(String args[]) {
        Integer[] arr = new Integer[] {3, 5, 2, 3, 1, 1, 1, 2, 6, 9, 7, 2};
         
        arr = remove_duplicates(arr);
         
        System.out.println(Arrays.toString(arr));
    }
}



/*
run:

[3, 5, 2, 1, 6, 9, 7]

*/

 

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