How to convert String to String array in Java?

In Java, a String is an object that represents the sequence of characters. In order to use Strings, we need to import the String class defined in java.lang package. The String array is an array of strings with a fixed length. In this section, we will learn how to convert String into String array.

Note: Java strings are immutable objects, i.e., the string value cannot be changed once it is created.

Converting String to String array

There are four ways to convert a String into String array in Java:

Using String.split() Method
Using Pattern.split() Method
Using String[ ] Approach
Using toArray() Method

Using String.split() Method

The String.split() method is used to split the string into individual strings entities based on the given delimiter (whitespace or other symbols). We can store these entities directly in a string array.

Let's consider the following example where we use String.split() method to convert a string into a string array.

TestSplitMethod.java

public class TestSplitMethod {
public static void main(String[] args) {
//declaring and initializing a string
String str = "Converting string to string array using split() method";
//declaring an empty string array
String[] strArray = null;
//converting using String.split() method with whitespace as a delimiter
strArray = str.split(" ");
//printing the converted string array
for (int i = 0; i< strArray.length; i++){
System.out.println(strArray[i]);
}
}
}

Output:

How to convert String to String array in Java

Example 2:

In the following example, we have converted the string to a string array based on the delimiter that is a , (comma).

TestSplitMethod2.java

public class TestSplitMethod2 {
public static void main(String[] args) {
String commaSeparatedStr = "Hello,have,a,nice,day";
String[] strArray = null;    //empty string array
//converting using String.split() method with comma as a delimiter
strArray = commaSeparatedStr.split(",");
//printing the converted string array
for (int i = 0; i< strArray.length; i++){
System.out.println(strArray[i]);
}
}
}

Output:

Using Pattern.split() Method

The Pattern.split() method is used to split the string into an array of strings with the help of regular expression (pattern) as the delimiter.

In order to use the method, we need to import the Pattern class in our Java code as:

Let's consider the following example where we split a string into an array by using the delimiter as whitespace.

SplitMethodOfPatternClass.java

//importing Pattern class
import java.util.regex.Pattern;
public class SplitMethodOfPatternClass {
public static void main(String[] args) {
//declaring and initializing a string
String str = "Converting string to string array using Pattern.split()";
//declaring an empty string array
String[] strArray = null;
//parsing white space as a parameter
Pattern ptr = Pattern.compile(" ");
//storing the string elements in array after splitting
strArray = ptr.split(str);
//printing the converted string array
for (int i = 0; i< strArray.length; i++){
System.out.println(strArray[i]);
}
}
}

Output:

Example 2:

We can also split a string into an array by using any string or pattern as a delimiter. Here, we have used the delimiter #a1.

SplitMethodOfPatternClass2.java

//importing Pattern class
import java.util.regex.Pattern;
public class SplitMethodOfPatternClass2 {
public static void main(String[] args) {
//declaring and initializing a string with a separator
String str = "Hello #a1Ben #a1how #a1are #a1you ?";
//declaring an empty string array
String[] strArray = null;
//splitting the string with delimiter as #a1
String patternStr = "#a1";
Pattern ptr = Pattern.compile(patternStr);
//storing the string elements in array after splitting
strArray = ptr.split(str);
//printing the converted string array
for (int i = 0; i< strArray.length; i++){
System.out.println(strArray[i]);
}
}
}

Output:

The above example splits the single string into five separate strings based on the delimiter #a1. The parts of the string that matched the delimiter are not included in the array.

Using String[ ] Approach

We can simply convert string to string array by using the string index [ ]. Here, we pass the string to String [ ] {}.

Consider the following example where we have used the String[] to convert a string into a string array.

StrToStrArray.java

import java.util.Arrays;
public class StrToStrArray {
public static void main(String[] args) {
//declaring and initializing a string
String str = "Converting string to string array using String[]";
//passing the string to String[] {}
String[] strArray = new String[] {str};
//printing the string array using Arrays.toString()
System.out.println(Arrays.toString(strArray));
}
}

Output:

Using toArray() Method

We can also convert String to String array by using the toArray() method of the List class. It takes a list of type String as the input and converts each entity into a string array.

Consider the following example where we have converted the list of strings into a string array.

StringListtoArray.java

//importing ArrayList and List class
import java.util.ArrayList;
import java.util.List;
public class StringListtoArray {
public static void main(String[] args) {
//creating a list of type string
List <String> list = new ArrayList <String> ();
//adding elements to list
list.add("Hello");
list.add("Welcome");
list.add("To");
list.add("Tutorial");
//size of list
int list_size = list.size();
//creating string array
String[] strArray = new String[list_size];
//converting to string array
list.toArray(strArray);
//printing the string array
for(int i = 0; i < strArray.length; i++) {
System.out.println(strArray[i]);
}
}
}

Output: