Splitting and joining strings

In Java, you can split a string into multiple substrings based on a delimiter, or you can join multiple strings into a single string using a delimiter. 

This can be useful for tasks such as parsing input, processing data, or formatting output. Here are some important details to consider:


Splitting strings:

The split() method is used to split a string into an array of substrings based on a specified delimiter.

It takes a regular expression pattern or a simple string delimiter as the parameter.

The method returns an array of substrings resulting from the split operation.

Example:


String message = "Hello,World,Java"; 
String[] parts = message.split(","); 
for (String part : parts) {
 System.out.println(part); 
}

In this example, the split() method is called on the message string with a comma (",") as the delimiter.

 The method splits the string at each occurrence of the delimiter and returns an array of substrings. 

The resulting substrings are then printed using a loop, producing the output:

Hello
World
Java

Joining strings:

To join multiple strings into a single string using a delimiter, you can use the join() method or the StringJoiner class introduced in Java 8.

The join() method takes a delimiter and an array or iterable of strings as parameters.

It concatenates the strings with the delimiter in between and returns the joined string.

Example using join():


String[] words = {"Hello", "World", "Java"}; 
String joinedString = String.join(", ", words);
 System.out.println(joinedString);

In this example, the join() method is called on the String class with a comma and a space (", ") as the delimiter and the words array as the input.

 The method joins the strings in the array with the delimiter in between, resulting in the output:


Hello, World, Java

Example using StringJoiner:


StringJoiner joiner = new StringJoiner(", "); 
joiner.add("Hello"); 
joiner.add("World"); 
joiner.add("Java"); 
String joinedString = joiner.toString(); 
System.out.println(joinedString);

In this example, the StringJoiner class is used to join the strings. 

The add() method is called to add each string to the joiner with the delimiter. 

Finally, the toString() method is used to obtain the joined string, joined string, producing the same output as the previous example:

Hello, World, Java

Splitting and joining strings are common operations when working with textual data. 

By utilizing the split() method or the join() method (or StringJoiner), you can easily split a string into substrings based on a delimiter or join multiple strings into a single string with a delimiter. 

These methods offer convenient ways to parse and process data, as well as format output in your Java programs.