IteratorDemo1.java

package Advances.CollectionDemo;

// https://www.youtube.com/watch?v=HA7LSr6-xls&list=PLmOn9nNkQxJH0qBIrtV6otI0Ep4o2q67A&index=525

/** Iterator demo 1 */
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import org.junit.jupiter.api.Test;

/**
 * Iterator Demo1 -> collection iteration op, via Iterator interface
 *
 * <p>1) internal method : hasNext(), and next() 2) collection will return an Iterator obj when
 * every call on iterator() (default idx is on the previous element) 3) remove() method can remove
 * element within iteration -> NOTE : Iterator's remove() is DIFFERENT from default remove method
 */
public class IteratorDemo1 {

  @Test
  public void test1() {

    /** remove() method in Iterator class */
    Collection col1 = new ArrayList();
    col1.add(123);
    col1.add(456);
    col1.add(789);
    col1.add("yooooo");
    col1.add("kate");
    col1.add(new Person("kyo", 19));

    Iterator iterator = col1.iterator();

    while (iterator.hasNext()) {
      Object obj = iterator.next();
      if ("kate".equals(obj)) {
        iterator.remove();
      }
    }

    System.out.println(col1);
  }
}