Converting ArrayList of Characters to a String?

Question

How to convert an ArrayList to a String in Java? The toString method returns it as [a,b,c] string - I wa

Answer 1

Many solutions available. You can iterate over the chars and append to a StringBuilder, then when finished appending, call .toString on the StringBuilder.

Or use something like commons-lang StringUtils.join from the apache commons-lang project.

Answer 2

a tiny complement to @waggledans 's answer

a) List of Character objects to String :

String str = chars.stream().map(e->e.toString()).collect(Collectors.joining());

which e->e.toString() can be replaced by Object::toString

String str = chars.stream().map(Object::toString).collect(Collectors.joining());

Answer 3

Here a possible one-line solution using Java8 streams.

a) List of Character objects to String :

String str = chars.stream().map(e->e.toString()).reduce((acc, e) -> acc  + e).get();

b) array of chars (char[] chars)

String str = Stream.of(chars).map(e->new String(e)).reduce((acc, e) -> acc  + e).get();

UPDATE (following comment below):

a) List of Character objects to String :

String str = chars.stream().map(e->e.toString()).collect(Collectors.joining());

b) array of chars (char[] chars)

String str = Stream.of(chars).map(e->new String(e)).collect(Collectors.joining());

Answer 4

How about this, Building the list

List<Character> charsList = new ArrayList<Character>();
charsList.add('h');
charsList.add('e');
charsList.add('l');
charsList.add('l');
charsList.add('o');

Actual code to get String from List of Character:

String word= new String();
for(char c:charsList){
word= word+ c; 
}
System.out.println(word);

Still learning if there is a misake point out.

Answer 5

Using join of a Joiner class:

// create character list and initialize 
List<Character> arr = Arrays.asList('a', 'b', 'c');   
String str = Joiner.on("").join(arr);
System.out.println(str);

Use toString then remove , and spaces

import com.google.common.base.Joiner; 

....
<Character> arr = Arrays.asList('h', 'e', 'l', 'l', 'o'); 
// remove [] and spaces 
String str = arr.toString() 
          .substring(1, 3 * str.size() - 1) //3 bcs of commas ,
          .replaceAll(", ", ""); 
System.out.println(str);

Or by using streams:

import java.util.stream.Collectors; 
...
// using collect and joining() method 
String str =  arr.stream().map(String::valueOf).collect(Collectors.joining());