What is the switch expression introduced in Java 12?

Table of Contents

• Introduction
• Features of the Switch Expression
  • 1. Concise Syntax
  • 2. Yield Keyword
  • 3. Enhanced Case Handling
  • 4. Use as an Expression
• Example of Switch Expression
  • Explanation of the Example
  • Benefits of the Switch Expression
• Conclusion

Introduction

The switch expression, introduced as a preview feature in Java 12, enhances the traditional switch statement by allowing it to be used as an expression. This new syntax improves code readability, reduces boilerplate code, and provides more flexibility in handling multiple cases. This guide explains the switch expression's features and how to use it effectively.

Features of the Switch Expression

1. Concise Syntax

The switch expression uses a more concise syntax that eliminates the need for the break statement, reducing boilerplate code.

2. Yield Keyword

In switch expressions, you can use the yield keyword to return a value from a case. This allows the expression to produce a result directly.

3. Enhanced Case Handling

You can combine multiple case labels to share a common block of code, similar to traditional switch statements, but with more clarity.

4. Use as an Expression

The switch expression can directly return a value, allowing you to assign the result to a variable without needing additional statements.

Example of Switch Expression

Here’s an example demonstrating the switch expression in Java 12:

Explanation of the Example

1. Variable Declaration: The variable dayOfWeek is declared and assigned a value of 5.
2. Switch Expression: The switch expression evaluates dayOfWeek and uses the arrow (->) syntax for each case. The matching case returns the corresponding day name.
3. Default Case: The default case handles invalid inputs, throwing an IllegalArgumentException if dayOfWeek is not between 1 and 7.

Benefits of the Switch Expression

• Readability: The concise syntax enhances readability, making it easier to understand the logic at a glance.
• Reduced Boilerplate: By removing the need for break statements, the code is cleaner and less error-prone.
• Flexible Return Values: The ability to return values directly from cases simplifies the assignment of results.

Conclusion

The switch expression introduced in Java 12 is a powerful enhancement to the traditional switch statement. By allowing switch to be used as an expression, it provides a more concise and readable way to handle multiple conditions. The addition of the yield keyword and improved case handling further enhances its usability. Understanding and using switch expressions can lead to cleaner, more maintainable Java code, making them a valuable tool for developers.