Question

i have one problem with my code ,i did a sample program to display the emp details from a linked list,now the problem when i trying to delete a particular entry means it doesn’t work,i hope i did some mistake in my code could you suggest how to do that?

import java.util.*;

class EmpDedup {
    int record;
    String fprint;
    int fid;

    EmpDedup(int record, String fprint, int fid) {
        this.record = record;
        this.fprint = fprint;
        this.fid = fid;
    }

    public int getRecord() {
        return record;
    }

    public String getFprint() {
        return fprint;
    }

    public int getFid() {
        return fid;
    }

    public static void main(String[] args) {
        int count = 0;
        LinkedList<EmpDedup> list = new LinkedList<EmpDedup>();
        list.add(new EmpDedup(101, "entry1", 20));
        list.add(new EmpDedup(102, "entry2", 30));
        list.add(new EmpDedup(103, "entry3", 40));
        list.add(new EmpDedup(104, "entry4", 50));

        Scanner input = new Scanner(System.in);
        System.out.print("Enter record no to display: ");
        int rec = input.nextInt();
        for (EmpDedup data : list) {
            if (data.getRecord() == rec) {
                System.out.println(data.getRecord() + "\t" + data.getFprint() + "\t" + data.getFid() + "\t");

                count++;

            }
        }
        System.out.println("The size of an linkedlist is: \t" + list.size());

        System.out.println("The number of  available record  is :" + count);

        System.out.println("The size of an linkedlist is: \t" + list.size());
        Scanner input1 = new Scanner(System.in);
        System.out.print("Enter record no to delete: ");// here i try to delete a particular record
        int rec1 = input1.nextInt();
        for (EmpDedup data : list) {
            if (data.getRecord() == rec1) {
                // System.out.println(data.getRecord()+"\t"+data.getFprint()+"\t"+data.getFid()+"\t");
                list.remove(data); // problem is here
                count++;

            }
        }
    }
}

Answer 1

you cannot operate in lists (add, remove… items) while you iterate on them. You have to use an Iterator

for(Iterator<EmpDedup> iter = list.iterator(); iter.hasNext();) {
    EmpDedup data = iter.next();
    if (data.getRecord() == rec1) {
        iter.remove();
    }
}

see http://docs.oracle.com/javase/6/docs/api/java/util/Iterator.html