How to Split a String in Java

This tutorial discusses how to split a string in Java.

String in Java is one of the non-primitive datatypes and is used to store a sequence of characters. We can declare a string variable simply as follows:

String string = "I am a string";
String string1 = "I am another string";

We might need to perform several string processing tasks, depending on what we are trying to achieve. Let’s consider the case where we have a string which represents data in a CSV format - all separated by a comma.

String data = "Apple,Banana,Orange,Peach";

We want all the individual strings from this; hence we need to split the string based on the comma to separate the data to get the following output.

> Apple
> Banana
> Orange
> Peach

Java Strings have a split function by default String#split() which takes a regular expression as input and returns an array of resulting strings after splitting on the given input.

The below example illustrates how to use this method to split a given string in Java.

public class Main {
  public static void main(String args[]) {
    String data = "Apple,Banana,Orange,Peach";
    String[] splitted = data.split(",");
    for (int i = 0; i < splitted.length; i++) {
      System.out.println(splitted[i]);
    }
  }
}

The above code outputs the following.

Apple
Banana
Orange
Peach

Let us try this method out to split a string on a different parameter.

Split on a Dot

This time we have a string like this: "One.Two.Three.Four". Let us use the same method again to split it.

public class Main {
  public static void main(String args[]) {
    String data = "One.Two.Three.Four";
    String[] splitted = data.split(".");
    for (int i = 0; i < splitted.length; i++) {
      System.out.println(splitted[i]);
    }
  }
}

The above code will output nothing! Remember, we mentioned that the split function takes a regular expression pattern as input. Therefore, we need to take extra measures when we want to split on some special characters.

There are 12 characters with special meanings:

• the backslash \
• the caret ^
• the dollar sign $
• the period or dot .
• the vertical bar or pipe symbol |
• the question mark ?
• the asterisk or star *
• the plus sign +
• the opening parenthesis (
• the closing parenthesis )
• and the opening square bracket [
• the opening curly brace {

These special characters are often called metacharacters.

If we want to split our string on any of the above characters, we can use backslash \ to escape these special characters, so use data.split('\\.') instead of data.split('.').

public class Main {
  public static void main(String args[]) {
    String data = "One.Two.Three.Four";
    String[] splitted = data.split("\\.");
    for (int i = 0; i < splitted.length; i++) {
      System.out.println(splitted[i]);
    }
  }
}

The above code now correctly outputs:

One
Two
Three
Four

Let us try one more example.

Split on a String

This time we have a string like this: "OneFruitTwoFruitThreeFruit". Let us use the same method again to split it based on the string Fruit.

public class Main {
  public static void main(String args[]) {
    String data = "OneFruitTwoFruitThreeFruit";
    String[] splitted = data.split("Fruit");
    for (int i = 0; i < splitted.length; i++) {
      System.out.println(splitted[i]);
    }
  }
}

The above code outputs:

One
Two
Three

Now we know how to split a string in Java on any given parameter.