Java String split(String regex) method example

java.lang.String split(String regex)

Description :

This java tutorial shows how to use the split(String regex) method of String class of java.lang package. This method returns a character array which corresponds to the result of splitting the String object given a java regular expression as a method parameter.

Method Syntax :

public String[] split(String regex)

Parameter Input :

Method Returns :

This String split() method with argument regex returns an array of String. The regex parameter will be used in evaluating how we can split the String object.

Compatibility Version :

Requires Java 1.5 and up

Exception :

PatternSyntaxException

This exception will be thrown if and only if the regex pattern specified on the method parameter is invalid.

Discussion :

I really can’t remember how many times do i have to use the split method. This is a very convenient method in breaking down a String object into smaller object based on the pattern provided as regex method parameter.

Supposed we have to break down a pipe(|) delimited String like for example we have a string object “Andrew|M|USA”. As you can see on our string object we have 3 token that we could extract. Using the String split method, we would be able to convert this object into String array.

Java Code Example :

This example source code demonstrates the use of [method name] method of String class. Basically it just converts a String object in the format Name:AGE:Country into a String array.

package com.javatutorialhq.java.tutorial.string;

/*
 * Java Example source code in splitting a string object
 * using String split(regex) method
 * Java tutorial
 */

public class StringSplitRegex {

	public static void main(String[] args) {
		// Declare string object
		String StringValue = "Andrew Carnegie:35:USA";
		// define the regex parameter
		String regex = ":";
		// split the string object
		String[]output = StringValue.split(regex);
		// printing the array contents
		System.out.println("Name:"+output[0]);
		System.out.println("Age:"+output[1]);
		System.out.println("Country:"+output[2]);

	}

}

Sample Output :

Running the split() method example source code of String class will give you the following output

Exception Scenario :

Exception in thread "main" java.util.regex.PatternSyntaxException: Dangling meta character '*' near index 0
*.
^
	at java.util.regex.Pattern.error(Unknown Source)
	at java.util.regex.Pattern.sequence(Unknown Source)
	at java.util.regex.Pattern.expr(Unknown Source)
	at java.util.regex.Pattern.compile(Unknown Source)
	at java.util.regex.Pattern.(Unknown Source)
	at java.util.regex.Pattern.compile(Unknown Source)
	at java.lang.String.split(Unknown Source)
	at java.lang.String.split(Unknown Source)
	at com.teknoscope.java.tutorial.string.StringSplitRegex.main(StringSplitRegex.java:17)

Similar Method :

• java.lang.String split(String regex, int limit)

Suggested Reading List :

• String Class Tutorial