Strings - Beginning Java 8 Fundamentals - page 393

Splitting and Joining Strings
It is often useful to split a string around a specified delimiter and join multiple strings into one string using a specified
delimiter.
Use the split() method to split a string into multiple strings. Splitting is performed using a delimiter.
The split() method returns an array of String . You will learn about arrays in Chapter 15. However, you will use
it in this section just to complete the operations of strings.

■ the split() method takes a regular expression that defines a pattern as a delimiter. i will discuss regular
expressions in Chapter 14.

Note

String str = "AL,FL,NY,CA,GA";
// Split str using a comma as the delimiter
String[] parts = str.split(",");
// Print the the string and its parts
System.out.println(str);

for(String part : parts) {
System.out.println(part);
}

AL,FL,NY,CA,GA
AL
FL
NY
CA
GA

Java 8 adds a static join() method to the String class that joins multiple strings into one string. It is
overloaded.

String join(CharSequence delimiter, CharSequence... elements) •

String join(CharSequence delimiter, Iterable<? extends CharSequence> elements) •

The first version takes a delimiter and a sequence of strings to be joined. The second version takes a delimiter
and an Iterable , for example, a List or Set . The following snippet of code uses the first version to join some strings:

// Join some strings using a comma as the delimiter
String str = String.join(",", "AL", "FL", "NY", "CA", "GA");
System.out.println(str);

AL,FL,NY,CA,GA