Question

Java

Write a method that removes duplicates from an array of strings and returns a new array, free of any duplicate strings.

Answer 1

import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashSet;
 
public class Main {
 public static String[] remove_duplicates(String[] courses){
     
     /*
         * convert array to list and then add all
         * elements to LinkedHashSet. LinkedHashSet
         * will automatically remove all duplicate elements. 
         */
        LinkedHashSet<String> linkedhashset =  
                new LinkedHashSet<String>(Arrays.asList(courses));
        
       
        String[] newArray = linkedhashset.toArray(new String[ linkedhashset.size() ]);
        
       
     return newArray;
 }
    public static void main(String[] args) {
        //original array
        String[] courses = {
                "c++",
                "c",
                "java",
                "c", //duplicate
                "python",
                "java"    //duplicate            
        };
        System.out.print("     original array             : ");
       for(int i=0;i<courses.length;i++){
           System.out.print(courses[i]+",");
       }
        
       String[] newArray=new String[courses.length];
       newArray=remove_duplicates(courses); 
       System.out.println();
         System.out.print("array after removing duplicates : ");
       for(int i=0;i<newArray.length;i++){
           System.out.print(newArray[i]+",");
       }
 
    }
}

.........................

• Java LinkedHashSet class contains unique elements.
• when string array is added to linkedhashset ,it automatically removes duplicate elements.This is advantage of using collections