Delete duplicate strings in string array

Question

I am making a program based on string processing in Java in which I need to remove duplicate strings from a string array. In this program, the size of all strings are same.

Answer 1

Set<String> set = new HashSet<String>();
Collections.addAll(set, array);

or start with

for(int s=0;s<array.length-1;s++)
{
    for(int m=s + 1;m<array.length;m++)
    {

                if(array[s] != null && array[s].equals(array[m]))
                {
                  // array = ArrayUtils.removeElement(array, array[s]); --m;??
                  array[m] = null; // Mark for deletion later on
                }
    } 
}

Answer 2

List<String> al = new ArrayList<String>();
String[] months={"Jan","Feb","Mar","Apr","Jan","Mar","May","May"};
for(int i=0;i<months.length;i++){
    for(int j=1;j<months.length;j++){
        if(months[i].equalsIgnoreCase(months[j])){
            if(!al.contains(months[i])){
                al.add(months[i]);
            }
        }
    }
}

Answer 3

Set data structure will do automatically the job for. Most likely option for you will be HashSet, if you care about the order of elements look at TreeSet

List<String> input = Arrays.asList(array);
Set<String> unique = new HashSet<>(input);

Answer 4

Proposed solution does not keep the order of the elements. If you use Java 8 or higher and want to maintain the order you can use streams as follows:

array = Arrays.stream(array).distinct().toArray(String[]::new);

Full example: https://www.javacodeexamples.com/java-string-array-remove-duplicates-example/849

Answer 5

     String[] arr = {"w10","w20","w10","w30","w20","w40","w50","w50"};
     List<String> arrList = new ArrayList<String>();
     int cnt= 0;
       //List<String> arrList = Arrays.asList(arr);
       List<String> lenList = new ArrayList<String>();
          for(int i=0;i<arr.length;i++){
        for(int j=i+1;j<arr.length;j++){
           if(arr[i].equals(arr[j])){
             cnt+=1;
           }                
        }
        if(cnt<1){
          arrList.add(arr[i]);
        }
          cnt=0;
        }

for(int k=0;k<arrList.size();k++){
            System.out.println("Array without Duplicates: "+arrList.get(k));
        }

Answer 6

This will work

array = new HashSet<String>(Arrays.asList(array)).toArray(new String[0]);

or just use a HashSet instead of an array.