Java String split()

 class Main { public static void main(String[] args) { String text = "Java is a fun programming language"; 
 // split string from space String[] result = text.split(" "); 
 System.out.print("result = "); for (String str : result) { System.out.print(str + ", "); } } } // Output: result = Java, is, a, fun, programming, language,

Syntax of String split()

The syntax of the string split() method is:

 string.split(String regex, int limit)

Here, string is an object of the String class.

split() Parameters

The string split() method can take two parameters:

• regex - the string is divided at this regex (can be strings)
• limit (optional) - controls the number of resulting substrings

If the limit parameter is not passed, split() returns all possible substrings.

split() Return Value

• returns an array of substrings

Note: If the regular expression passed to split() is invalid, the split() method raises PatternSyntaxExpression exception.

Example 1: split() Without limit Parameter

 // importing Arrays to convert array to string // used for printing arrays import java.util.Arrays; class Main { public static void main(String[] args) { String vowels = "a::b::c::d:e"; // splitting the string at "::" // storing the result in an array of strings 
 String[] result = vowels.split("::"); 
 // converting array to string and printing it System.out.println("result = " + Arrays.toString(result)); } }

Output

 result = [a, b, c, d:e]

Here, we split the string at ::. Since the limit parameter is not passed, the returned array contains all the substrings.

split() With limit Parameter

• If the limit parameter is 0 or negative, split() returns an array containing all substrings.
• If the limit parameter is positive (let's say n), split() returns the maximum of n substrings.

Example 2: split() With limit Parameter

 // importing Arrays to convert array to string import java.util.Arrays; class Main { public static void main(String[] args) { String vowels = "a:bc:de:fg:h"; // splitting array at ":" // limit is -2; array contains all substrings 
 String[] result = vowels.split(":", -2); 
 System.out.println("result when limit is -2 = " + Arrays.toString(result)); // limit is 0; array contains all substrings result = vowels.split(":", 0); System.out.println("result when limit is 0 = " + Arrays.toString(result)); // limit is 2; array contains a maximum of 2 substrings result = vowels.split(":", 2); System.out.println("result when limit is 2 = " + Arrays.toString(result)); // limit is 4; array contains a maximum of 4 substrings result = vowels.split(":", 4); System.out.println("result when limit is 4 = " + Arrays.toString(result)); // limit is 10; array contains a maximum of 10 substrings result = vowels.split(":", 10); System.out.println("result when limit is 10 = " + Arrays.toString(result)); } }

Output

 result when limit is -2 = [a, bc, de, fg, h] result when limit is 0 = [a, bc, de, fg, h] result when limit is 2 = [a, bc:de:fg:h] result when limit is 4 = [a, bc, de, fg:h] result when limit is 10 = [a, bc, de, fg, h]

Note: The split() method takes regex as the first argument. If you need to use special characters such as: \, |, ^, *, + etc, you need to escape these characters. For example, we need to use \\+ to split at +.

Example 3: split() at the + character

 // importing Arrays to convert array to string // used for printing arrays import java.util.Arrays; class Main { public static void main(String[] args) { String vowels = "a+e+f"; 
 // splitting the string at "+" String[] result = vowels.split("\\+"); 
 // converting array to string and printing it System.out.println("result = " + Arrays.toString(result)); } }

Output

 result = [a, e, f]

Here, to split a string at +, we have used \\+. It's because + is a special character (has a special meaning in regular expressions).