An ArrayList to an Array Conversion - Java Collection Framework

Java examples for Collection Framework:ArrayList

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Description

An ArrayList to an Array Conversion

Demo Code

import java.util.ArrayList; 
import java.util.Arrays;

public class Main {
  public static void main(String[] args){
    ArrayList<String> al = new ArrayList<String>();
    al.add("cat");
    al.add("dog");
    al.add("rat");

    // Print the content of arrayList
    System.out.println("ArrayList:" + al);
    //from  w w  w .ja  va  2s .  c  om
    // Create an array of the same length as the ArrayList
    String[] s1 = new String[al.size()];
    
    // Copy the ArrayList elements to the array
    String[] s2 = al.toArray(s1);
    
    System.out.println("s1 == s2:" + (s1 == s2));
    System.out.println("s1:" + Arrays.toString(s1));
    System.out.println("s2:" + Arrays.toString(s2));


    // Create an array of string with 1 element.
    s1 = new String[1];
    s1[0] = "hello" ; // Store hello in first element

    // Copy ArrayList to the array s1
    s2 = al.toArray(s1);

    System.out.println("s1 == s2:" + (s1 == s2));
    System.out.println("s1:" + Arrays.toString(s1));
    System.out.println("s2:" + Arrays.toString(s2));
  }
}

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