Converting String array to java.util.List
JavaArraysCollectionsJava Problem Overview
How do I convert a String
array to a java.util.List
?
Java Solutions
Solution 1 - Java
List<String> strings = Arrays.asList(new String[]{"one", "two", "three"});
This is a list view of the array, the list is partly unmodifiable, you can't add or delete elements. But the time complexity is O(1).
If you want a modifiable a List:
List<String> strings =
new ArrayList<String>(Arrays.asList(new String[]{"one", "two", "three"}));
This will copy all elements from the source array into a new list (complexity: O(n))
Solution 2 - Java
Use the static List list = Arrays.asList(stringArray)
or you could just iterate over the array and add the strings to the list.
Solution 3 - Java
import java.util.Collections;
List myList = new ArrayList();
String[] myArray = new String[] {"Java", "Util", "List"};
Collections.addAll(myList, myArray);
Solution 4 - Java
The Simplest approach:
String[] stringArray = {"Hey", "Hi", "Hello"};
List<String> list = Arrays.asList(stringArray);
Solution 5 - Java
First Step you need to create a list instance through Arrays.asList();
String[] args = new String[]{"one","two","three"};
List<String> list = Arrays.asList(args);//it converts to immutable list
Then you need to pass 'list' instance to new ArrayList();
List<String> newList=new ArrayList<>(list);
Solution 6 - Java
As of Java 8 and Stream API you can use Arrays.stream
and Collectors.toList
:
String[] array = new String[]{"a", "b", "c"};
List<String> list = Arrays.stream(array).collect(Collectors.toList());
This is practical especially if you intend to perform further operations on the list.
String[] array = new String[]{"a", "bb", "ccc"};
List<String> list = Arrays.stream(array)
.filter(str -> str.length() > 1)
.map(str -> str + "!")
.collect(Collectors.toList());
Solution 7 - Java
On Java 14 you can do this
List<String> strings = Arrays.asList("one", "two", "three");