Java ArrayList clear() Method Example

ArrayList Methods with Examples

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• Java ArrayList add() Method
• Java ArrayList addAll() Method
• Java ArrayList clear() Method
• Java ArrayList contains() Method
• Java ArrayList ensureCapacity() Method
• Java ArrayList clone() Method
• Java ArrayList get() Method
• Java ArrayList indexOf() Method
• Java ArrayList remove() Method
• Java ArrayList removeAll() Method
• Java ArrayList removeIf() Method
• Java ArrayList retainAll() Method
• Java ArrayList sort() Method
• Java ArrayList spliterator() Method

Java ArrayList Examples

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• Java ArrayBlockingQueue Example
• Java Convert Array to Set
• Copying part of Array in Java Example
• Sorting an Array using Arrays.sort() Method
• Check Two Arrays are Deeply Equal
• Java Arrays.copyOf() Example - Copying an Array
• Java Arrays.binarySearch() Example - Searching an Array
• Java Arrays.asList() Example - Convert Array to ArrayList
• Java Convert Array to Stack Example
• What's the Simplest Way to Print a Java Array?
• Java Pyramid Examples
• How to Check if Two Arrays are Equal in Java
• Create and Initialize Two Dimensional Array in Java
• How to Initialize an Array in Java in One Line
• Java Array - Create, Declare, Initialize and Print Examples
• Java Array Simple Program

The java.util.ArrayList.clear() method removes all of the elements from this list. The list will be empty after this call returns.

Java ArrayList clear() Method Example

The following example shows the usage of java.util.Arraylist.clear() method.

import java.util.ArrayList;

public class ArrayListDemo {
   public static void main(String[] args) {
     
      // create an empty array list with an initial capacity
      ArrayList<Integer> arrlist = new ArrayList<Integer>(5);

      // use add() method to add elements in the list
      arrlist.add(20);
      arrlist.add(30);
      arrlist.add(10);
      arrlist.add(50);

      // let us print all the elements available in list
      for (Integer number : arrlist) {
         System.out.println("Number = " + number);
      }      

      // finding size of this list
      int retval = arrlist.size();
      System.out.println("List consists of "+ retval +" elements");
         
      System.out.println("Performing clear operation !!");
      arrlist.clear();
      retval = arrlist.size();
      System.out.println("Now, list consists of "+ retval +" elements");
   }
}   

Let us compile and run the above program, this will produce the following result −

Number = 20
Number = 30
Number = 10
Number = 50
List consists of 4 elements
Performing clear operation !!
Now, list consists of 0 elements

Reference

https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/util/ArrayList.html