Java - split string by space character

1. Overview

In Java there is a couple of ways to split string by space.

String example = "How to split string by space?";

// simple split by space char
String[] split1 = example.split(" ");

// split by whitespace regex - \\s 
String[] split2 = example.split("\\s");

// split by whitespace regex once or more - \\s+
String[] split3 = example.split("\\s+");

2. Java simple split by space char

Code example:

public class JavaSplitBySpaceExample1 {

    public static void main(String[] args) {

        String example = "How to split string by space?";
        String[] split = example.split(" ");

        System.out.println("# Original string: ");
        System.out.println(example);
        System.out.println();

        System.out.println("# Split by space string: ");
        int cnt = 1;
        for (String str : split) {
            System.out.println(cnt + " - " + str);
            cnt++;
        }
    }
}

Output:

# Original string:
How to split string by space?

# Split by space string:
1 - How
2 - to
3 - split
4 - string
5 - by
6 - space?

3. Java split by whitespace regex - \\s 

Code example:

public class JavaSplitBySpaceExample2 {

    public static void main(String[] args) {

        String example = "How to split string by space?";
        String[] split = example.split("\\s");

        System.out.println("# Original string: ");
        System.out.println(example);
        System.out.println();

        System.out.println("# Split by space string: ");
        int cnt = 1;
        for (String str : split) {
            System.out.println(cnt + " - " + str);
            cnt++;
        }
    }
}

Output:

# Original string:
How to split string by space?

# Split by space string:
1 - How
2 - to
3 - split
4 - string
5 - by
6 - space?

4. Java split by whitespace regex once or more - \\s+

Code example:

public class JavaSplitBySpaceExample3 {

    public static void main(String[] args) {

        String example = "How       to split string by  space?";
        String[] split = example.split("\\s+");

        System.out.println("# Original string: ");
        System.out.println(example);
        System.out.println();

        System.out.println("# Split by space string: ");
        int cnt = 1;
        for (String str : split) {
            System.out.println(cnt + " - " + str);
            cnt++;
        }
    }
}

Output:

# Original string: 
How       to split string by  space?

# Split by space string: 
1 - How
2 - to
3 - split
4 - string
5 - by
6 - space?