How to remove duplicate values From String Array

Question

I am using the following code and this is giving me a duplicate values in every position of the array So suggest me what to do

String sCurrentLine;
String username[] = new String[30];
String Arrival[] = new String[30];
String Departure[] = new String[30];
int var = 0, var2;
BufferedReader br = new BufferedReader(new FileReader("E:\\Shubham Projects\\Input.txt"));

while ((sCurrentLine = br.readLine()) != null) {
    String[] information = sCurrentLine.split(" ");
    var2 = information.length + var;
    for (int i = var; i < var2; i++) {
        System.out.println(i);
        username[i] = information[0];
        Arrival[i] = information[1];
        Departure[i] = information[2];
        var++;
    }

}
for (int i = 0; i < username.length; i++)
    System.out.println(username[i] + " " + Arrival[i] + " " + Departure[i]);

Input:

Jai 10:15 11:10
Jai 10:10 11:00
Veeru 10:10 11:00
Veeru 16:30 18:45
Jai 12:05 12:30
Veeru 12:30 13:25
Veeru 12:45 13:25
Jai 17:25 18:01

Output:

Jai 10:15 11:10
Jai 10:15 11:10
Jai 10:15 11:10
Jai 10:10 11:00
Jai 10:10 11:00
Jai 10:10 11:00
Veeru 10:10 11:00
Veeru 10:10 11:00
Veeru 10:10 11:00
Veeru 16:30 18:45
Veeru 16:30 18:45
Veeru 16:30 18:45
Jai 12:05 12:30
Jai 12:05 12:30
Jai 12:05 12:30
Veeru 12:30 13:25
Veeru 12:30 13:25
Veeru 12:30 13:25
Veeru 12:45 13:25
Veeru 12:45 13:25
Veeru 12:45 13:25
Jai 17:25 18:01
Jai 17:25 18:01
Jai 17:25 18:01
null null null
null null null
null null null
null null null
null null null
null null null

Jai 10:15 11:10 Jai 10:10 11:00 Veeru 10:10 11:00 Veeru 16:30 18:45 Jai 12:05 12:30 Veeru 12:30 13:25 Veeru 12:45 13:25 Jai 17:25 18:01 — Shubham Jaiswal
– Shubham Jaiswal, Commented Sep 12, 2015 at 14:01
What is the problem then ?? Input and output matched right ? — Suresh Atta
– Suresh Atta, Commented Sep 12, 2015 at 14:02
No where you are checking the duplicates and also input & ouput got matched right? — Shriram
– Shriram, Commented Sep 12, 2015 at 14:04
Please check the post again, because by mistake I have uploaded the Input file in place of Output... Now Can you give me the solution??? @Suresh ATTA — Shubham Jaiswal
– Shubham Jaiswal, Commented Sep 12, 2015 at 14:07

Amila · Accepted Answer · 2015-09-12 13:59:22Z

2

You can use Set data structure which allows no duplicates.

Try:

    Set<String> resultSet = new HashSet<String>(Arrays.asList(username));

resultSet will have unique Strings.

edited Sep 12, 2015 at 13:59

answered Sep 12, 2015 at 13:55

Amila

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2 Comments

Suresh Atta Over a year ago

Good solution but can you tell, what is the issue with current code ?

Shubham Jaiswal Over a year ago

The issue is the code is printing duplicate values in all the array that I used in the code

slm · Accepted Answer · 2015-12-03 17:47:39Z

1

Inner for loop is causing the issue because you're grabbing the information from every line three times.

var2 = information.length + var;
for (int i = var; i < var2; i++) {
    System.out.println(i);
    username[i] = information[0];
    Arrival[i] = information[1];
    Departure[i] = information[2];
    var++;
}

For example:

Jai 10:15 11:10

When you read this line, var2 will evaluate to 3 (assuming var is 0). Now it'll run through the for loop three times, giving you your duplicate entries.

Shriram's solution will fix this issue and Amila's response will fix the issue of duplicate entries in the input file.

edited Dec 3, 2015 at 17:47

slm

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answered Sep 12, 2015 at 15:03

cogan

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Comments

Shriram · Accepted Answer · 2015-09-12 14:17:58Z

0

Make use of set and print the result, because Set won't allow duplicates.

Use the below logic

int count = 0;
        while ((sCurrentLine = br.readLine()) != null) {
            String[] information = sCurrentLine.split(" ");
            // for (int i = 0; i < information.length; i++) {
            username[count] = information[0];
            Arrival[count] = information[1];
            Departure[count] = information[2];
            // }
            count++;
        }

After printing the output the remaining null values are nothing but you have initalized string array with 30. Make use of collection classes for dynamic array. Also i said make use of Set to avoid duplicated

edited Sep 12, 2015 at 14:17

answered Sep 12, 2015 at 13:55

Shriram

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1 Comment

Suresh Atta Over a year ago

Good solution but can you tell, what is the issue with current code ?

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