String array to arraylist

[vani mn]

How to convert a string array to arraylist??

[Garrett Rowe]

If the concrete implementation doesn't matter, you can use Arrays.asList() to convert your array to a List.

import java.util.Arrays;
import java.util.List;
import java.util.ArrayList;
public class StringArrayTest
{
   public static void main(String[] args)
   {
      String[] words = {"ace", "boom", "crew", "dog", "eon"};
 
      List<String> wordList = Arrays.asList(words);
 
      for (String e : wordList)
      {
         System.out.println(e);
      }
   }
}

[Ernest Friedman-Hill]

Otherwise, there's always

new ArrayList(Arrays.asList(myArray));

[Ken Blair]

Or

String[] words = { ... };
List<String> list = new ArrayList<String>(words.length);
for (String s : words) {
    list.add(s);
}

[Janarthan S Sathiamurthy]

import java.util.Collections;

List myList = new ArrayList();
String[] myStringArray = new String[] {"Java", "is", "Cool"};

Collections.addAll(myList, myStringArray);

After this code, 'myList' should contain all the elements from the array.

Best regards,
Janarthan S

[Ziyang Zhang]

Janarthan S Sathiamurthy wrote:import java.util.Collections;

List myList = new ArrayList();
String[] myStringArray = new String[] {"Java", "is", "Cool"};

Collections.addAll(myList, myStringArray);

After this code, 'myList' should contain all the elements from the array.

Best regards,
Janarthan S

Good solution!!!

[Jesper de Jong]

There are some important things to note with the solutions given above:

Garrett's solution, with Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception.

Ernest's solution: new ArrayList(Arrays.asList(myArray)); copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Janarthan's solution, with Collections.addAll(myList, myStringArray); is essentially the same as Ernest's solution.

If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Garrett's solution. Otherwise use Ernest's or Janarthan's solution.

[Ziyang Zhang]

Jesper Young wrote:There are some important things to note with the solutions given above:

Garrett's solution, with Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception.

Ernest's solution: new ArrayList(Arrays.asList(myArray)); copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Janarthan's solution, with Collections.addAll(myList, myStringArray); is essentially the same as Ernest's solution.

If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Garrett's solution. Otherwise use Ernest's or Janarthan's solution.

These are great comments.
But I think in most conditions, people will want to make a "static" array to a "dynamic" arraylist.

[Hunter McMillen]

You have to be careful with the kind of terminology you use. "static" is a keyword in Java that has a particular meaning. By saying "static" array I think you mean "fixed-size" array. A "static" array in Java is an array that belongs to a particular instance of a class.

Hunter

[Muhammad Safwat]

Jesper Young wrote:There are some important things to note with the solutions given above:

Garrett's solution, with Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception.

Ernest's solution: new ArrayList(Arrays.asList(myArray)); copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Janarthan's solution, with Collections.addAll(myList, myStringArray); is essentially the same as Ernest's solution.

If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Garrett's solution. Otherwise use Ernest's or Janarthan's solution.

Very good analysis and you need to add also that copying the array affects the performance of your code so if performance is an issue then user the Arrays.asList() way

[Colin Wang]

Perfect comments.
Thank you.

Jesper de Jong wrote:There are some important things to note with the solutions given above:

Garrett's solution, with Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception.

Ernest's solution: new ArrayList(Arrays.asList(myArray)); copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Janarthan's solution, with Collections.addAll(myList, myStringArray); is essentially the same as Ernest's solution.

If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Garrett's solution. Otherwise use Ernest's or Janarthan's solution.

[Campbell Ritchie]

Welcome to the Ranch colin wang

[Kaustubh G Sharma]

Jesper de Jong wrote:There are some important things to note with the solutions given above:

Garrett's solution, with Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception.

Ernest's solution: new ArrayList(Arrays.asList(myArray)); copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Janarthan's solution, with Collections.addAll(myList, myStringArray); is essentially the same as Ernest's solution.

If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Garrett's solution. Otherwise use Ernest's or Janarthan's solution.

Jesper you really rocks man...Wonderful explanation...keep up the good work

[anbu selvan]

we can add array of string to List

it is one more option to add string to list

String na ={"anbu","selvan","raja"};
ArrayList ar = new ArraList();
List list = Collections.addAll(ar,na);

[Rob Spoor]

Anbu, welcome to the Ranch!

Your code won't compile - Collections.addAll returns a boolean, not a List.

[Ming Wilson]

Kaustubh G Sharma wrote:

Jesper de Jong wrote:There are some important things to note with the solutions given above:

Garrett's solution, with Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception.

Ernest's solution: new ArrayList(Arrays.asList(myArray)); copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Janarthan's solution, with Collections.addAll(myList, myStringArray); is essentially the same as Ernest's solution.

If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Garrett's solution. Otherwise use Ernest's or Janarthan's solution.

Jesper you really rocks man...Wonderful explanation...keep up the good work

Excellent comment.

[Campbell Ritchie]

Welcome to the Ranch Ming Wilson

[Ming Wilson]

Campbell Ritchie wrote:Welcome to the Ranch Ming Wilson

Thank you very much, I have been referred to this site a 1000's of times in relations to problems that I have googled and have always found the responses of similar problems to be helpful, inciteful and non degrading of the developer, but I do love the mentioning of best practices.

I look forward to our mutual journey through Java together.

[Vinay M Raju]

Jesper de Jong wrote:There are some important things to note with the solutions given above:

Garrett's solution, with Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception.

Ernest's solution: new ArrayList(Arrays.asList(myArray)); copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Janarthan's solution, with Collections.addAll(myList, myStringArray); is essentially the same as Ernest's solution.

If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Garrett's solution. Otherwise use Ernest's or Janarthan's solution.

Excellent comment. These are the pearls of wisdom we look forward to in this forum. Thanks a lot.

[rk sharma]

Using asList() method is the best way

[Vijitha Kumara]

And welcome to CodeRanch, Vinay Mr!

[chan nyeinkyaw]

Jesper de Jong wrote:There are some important things to note with the solutions given above:

Garrett's solution, with Arrays.asList() is efficient because it doesn't need to copy the content of the array. This method returns a List that is a "view" onto the array - a wrapper that makes the array look like a list. When you change an element in the list, the element in the original array is also changed. Note that the list is fixed size - if you try to add elements to the list, you'll get an exception.

Ernest's solution: new ArrayList(Arrays.asList(myArray)); copies the content of the array to a new ArrayList. The copy is ofcourse independent of the array, and you can add, remove etc. elements as you like.

Janarthan's solution, with Collections.addAll(myList, myStringArray); is essentially the same as Ernest's solution.

If you only need read access to the array as if it is a List and you don't want to add or remove elements from the list, then use Garrett's solution. Otherwise use Ernest's or Janarthan's solution.

nice comments
Thanks