Question

How to Iterate over unmodifiable collection in Java

Answer 1

package javaapplication1;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

public class JavaApplication1 {

    public static void main(String[] args) {

        List<String> list = new ArrayList<>();
 
        list.add("aaa");
        list.add("bbb");
        list.add("ccc");
        list.add("ddd");

        System.out.println(list.get(0));
        System.out.println(list.get(1));

        Collection<String> unmodifiable = Collections.unmodifiableCollection(list);

        Iterator<String> iterator = unmodifiable.iterator();

        System.out.println();
        while (iterator.hasNext()) 
            System.out.println(iterator.next());
  }
}
  
/*
run:

aaa
bbb

aaa
bbb
ccc
ddd

*/

 

70+ SQL courses for beginners and professionals