Friday, 25 August 2017

Java Program to convert String ArrayList to String Array

Converting String ArrayList into String array is very common programming task in Java. you often need to convert Array to Array List in Java  and vice-versa. In this Java program, we will How to convert String ArrayList to String array. This is also a common programming exercise which is asked too many Java programmers in various Java related courses. It’s also worth noting that ArrayList in Java is internally backed by array and Array in Java are objects much like String which is also an Object in Java. In this Java program, we first create an ArrayList which stores name of months as String e.g. Jan, Feb, and Mar. Later we use ArrayList  toArray() method to convert ArrayList into an array.

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How to convert String ArrayList to Array in Java


How to convert String ArrayList to String Array in JavaHere is full code example of Java test program which convert String ArrayList to String Array in Java.In this Java program we first create an ArrayList which stores name of month in String format and then we convert that into an String array.

Java Program to convert an ArrayList of String to an Array


package arrayListEx;

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

public class ArrayListtoArray {
   
        public static void main(String args[]){
           
                //ArrayList containing string objects
                ArrayList<String> aListMonth = new ArrayList<String>();
                aListMonth.add("Jan");
                aListMonth.add("Feb");
                aListMonth.add("mar");
           
                /*
                 * To convert ArrayList containing String elements to String array, use
                 * Object[] toArray() method of ArrayList class.
                 */
           
                //First Step: convert ArrayList to an Object array.
                Object[] objMnt = aListMonth.toArray();
           
                //Second Step: convert Object array to String array
                String[] strMnts = Arrays.copyOf(objMnt, objMnt.length, String[].class);
           
                System.out.println("ArrayList converted to String array");
           
                //print elements of String array
                for(int i=0; i < strMnts.length; i++){
                        System.out.println(strMnts[i]);
                }
        }
}