In this Java tutorial, you will learn how to convert string array to an ArrayList of strings using For loop, or ArrayList.addAll() method, with examples.
Convert String Array to ArrayList in Java
To convert String Array to ArrayList<String> in Java, we can use for loop or Arrays Class. In this tutorial, we shall go through some examples where we convert a String[] to ArrayList<String>.
Examples
1. String[] to ArrayList<String> using For Loop
In the following example, we will initialize an empty ArrayList and add the items of string array one by one to this ArrayList using a For loop.
Example.java
import java.util.ArrayList;
public class Example {
public static void main(String[] args) {
// string array
String[] names = {"Java","Kotlin","Android"};
// declare an arraylist that hold strings
ArrayList<String> nameList = new ArrayList<String>();
// add each element of string array to arraylist
for(String name:names) {
nameList.add(name);
}
// print the arraylist
nameList.forEach(name ->{
System.out.println(name);
});
}
}
Output
Java
Kotlin
Android
2. String Array to ArrayList using ArrayList.addAll() and Arrays.asList()
To convert String Array to ArrayList, we can make use of Arrays.asList() function and ArrayList.addAll().
Arrays.asList(String[])
returns List<String>
with elements of String[]
loaded to List<String>
.
Now, we can make use of ArrayList.addAll(List<String>)
that adds elements of List to the ArrayList.
Example.java
import java.util.ArrayList;
import java.util.Arrays;
public class Example {
public static void main(String[] args) {
// string array
String[] names = {"Java","Kotlin","Android"};
// declare an arraylist that hold strings
ArrayList<String> nameList = new ArrayList<String>();
// add elements of array to arraylist
nameList.addAll(Arrays.asList(names));
// print the arraylist
nameList.forEach(name ->{
System.out.println(name);
});
}
}
Output
Java
Kotlin
Android
Conclusion
In this Java Tutorial, we learned how to convert String Array to ArrayList.
Using for Loop is better than the latter approach. When we are using Arrays.asList()
function, an intermediate List<String> is created, which is avoided when for loop is used.