Chapter 1: Introduction to PHP 8's Match Expression

The introduction of the match expression in PHP 8.0 marks a significant enhancement in the language's functionality. This feature is often a more efficient alternative to the traditional switch statement. The match expression facilitates branching based on an identity comparison of values, which is akin to how a switch statement operates. However, unlike switch, the match expression evaluates to a value, resembling ternary expressions. Notably, the comparison in match uses strict identity checks (===) rather than the loose equality checks (==) found in switch.

Chapter 2: Comparing Match and Switch

To fully appreciate the differences between match and switch, let's look at an example. Here is a conventional switch statement:

In contrast, the equivalent match expression is much more concise:

The key benefits of using the match expression include:

• Reduced syntax requiring no break statements to avoid fall-through.
• The ability to combine different cases into one line using commas.
• Returning a value, allowing for easier assignment without the complexity of multiple returns.

Thus, match expressions are syntactically simpler and easier to implement.

Section 2.1: Unique Characteristics of Match

One significant aspect of the match expression is its strict type checking, which might not always suit cases where PHP's type juggling is desirable. Consequently, replacing all switch statements with match expressions isn't feasible in every scenario.

When using a match expression, if an unknown value is encountered and no default case is defined, PHP will raise an UnhandledMatchError. While this may seem restrictive, it helps prevent subtle bugs from going unnoticed.

Currently, match expressions allow only one expression per line and do not permit fall-through conditions. However, combining multiple conditions on the same line with commas is possible.

Section 2.2: Exception Handling in Match

With the introduction of throw expressions in PHP 8.0, you can also throw exceptions directly from within a match arm, enhancing its flexibility:

Chapter 3: Choosing Between Switch and Match

In summary, the match expression serves as a stricter and more modern alternative to the switch statement. While switch can provide necessary flexibility in certain situations, the strictness of match can often be a more advantageous choice.

Overview of Match Expression in PHP 8

Beginner PHP Tutorial on Expression Matching