- Given an arraylist containing string objects, we would like to remove or delete elements from arraylist collection.
- Arraylist has following methods to remove or delete element(s)/nodes/objects.
| No. | Method name | Description |
|---|
| 1 | E remove(int index) | Removes the element at the specified position in this list. |
| 2 | boolean remove(Object o) | Removes the first occurrence of the specified element from this list, if it is present. |
| 3 | boolean removeAll(Collection<?> c) | Removes from this list all of its elements that are contained in the specified collection. |
Program – remove or delete elements/nodes from arraylist in java
package org.learn.collection.list.arrayList;
import java.util.ArrayList;
public class DemoRemoveInArrayList {
public static void main(String[] args) {
ArrayList<String> arrayList = new ArrayList<>();
arrayList.add("archery");
arrayList.add("badminton");
arrayList.add("canoe");
arrayList.add("boxing");
arrayList.add("diving");
arrayList.add("cycling");
arrayList.add("rowing");
System.out.println("Demo of remove methods: ");
demoRemoveMethod(arrayList);
}
private static void demoRemoveMethod(ArrayList<String> arrayList) {
// [archery, badminton, canoe, boxing, diving, cycling, rowing]
System.out.println("1. Orignal ArrayList:" + arrayList);
// Remove element by index
arrayList.remove(0);
// [badminton, canoe, boxing, diving, cycling, rowing]
System.out.println("2. Removed element at 0 index: " + arrayList);
// Remove element after comparing and remove it
arrayList.remove("boxing");
// [badminton, canoe, diving, cycling, rowing]
System.out.println("3. Removed boxing from arrayList: " + arrayList);
ArrayList<String> removeElementsList = new ArrayList<>();
removeElementsList.add("canoe");
removeElementsList.add("diving");
// Remove element by supplying another collection
arrayList.removeAll(removeElementsList);
// [badminton, cycling, rowing]
System.out.println("4. Removed collection containing canoe and diving: " + arrayList);
}
}
Output – remove or delete objects/nodes from arraylist collection in java
Demo of remove methods:
1. Orignal ArrayList:[archery, badminton, canoe, boxing, diving, cycling, rowing]
2. Removed element at 0 index: [badminton, canoe, boxing, diving, cycling, rowing]
3. Removed boxing from arrayList: [badminton, canoe, diving, cycling, rowing]
4. Removed collection containing canoe and diving: [badminton, cycling, rowing]
