Split String in Java

Split String in Java

You can split a String by whitespaces or tabs in Java by using the split() method of java.lang.String class. This method accepts a regular expression and you can pass a regex matching with whitespace to split the String where words are separated by spaces.

This java program has demonstrated to split a String by single or multiple whitespaces or tabs in Java.

Program:

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStreamReader;

public class StringSplitDemo {

       public static void main(String[] args) {

              // TODO Auto-generated method stub

              String line;

              String[] words;

              BufferedReader reader = new BufferedReader(new InputStreamReader(

                           System.in));

             

              System.out.println("input string words separated by space: ");            

              try {

                     line = reader.readLine();

                     words = line.split(" ");

                     System.out.println("output string: ");

                     for (int i = 0; i < words.length; i++)

                           System.out.println(words[i]);

              } catch (IOException e) {

                     // TODO Auto-generated catch block

                     e.printStackTrace();

              }

              System.out.println("input string words separated by multiple space: ");

              try {

                     line = reader.readLine();

                     words = line.split("\\s+");

                     System.out.println("output string: ");

                     for (int i = 0; i < words.length; i++)

                           System.out.println(words[i]);

              } catch (IOException e) {

                     // TODO Auto-generated catch block

                     e.printStackTrace();

              }

             

              System.out.println("input string with leading and trailing space: ");

              try {

                     line = reader.readLine();

                     words = line.trim().split("\\s+");

                     System.out.println("output string: ");

                     for (int i = 0; i < words.length; i++)

                           System.out.println(words[i]);

              } catch (IOException e) {

                     // TODO Auto-generated catch block

                     e.printStackTrace();

              }

       }

}

Output:

input string words separated by space:

Hi Friends, My Name is Piyush Patel

output string:

Hi

Friends,

My

Name

is

Piyush

Patel

input string words separated by multiple space:

Hi      Friends,  My       name is              Piyush  Patel

output string:

Hi

Friends,

My

name

is

Piyush

Patel

input string with leading and trailing space:

     My Name is Piyush Patel   

output string:

My

Name

is

Piyush

Patel

Important points about split() method:

1. Splits this string around matches of the given regular expression.
2. Returns the array of strings computed by splitting this string around matches of the given regular expression
3. The split() method throws PatternSyntaxException - if the regular expression's syntax is invalid
4. This method was added to Java 1.4, so it's not available to the earlier version but you can use it in Java 5, 6, 7 or 8 because Java is backward compatible.

To split string using delimiter like comma, colon, space etc.:

String mystr = "Red,Green,Yellow,Pink,Blue";

       String[] splits = mystr.split(",");

             

       System.out.println("splits.size: " + splits.length);

       for(String x: splits)

       {

              System.out.println(x);

       }

Output:

splits.size: 5

Red

Green

Yellow

Pink

Blue

String split example using StringTokenizer

       mystr = "1:22:333:4444:55555";

       StringTokenizer stringtokenizer = new StringTokenizer(mystr, ":");

       while (stringtokenizer.hasMoreElements())

       {

              System.out.println(stringtokenizer.nextToken());

}

Output:

1

22

333

4444

55555