The match expression in PHP8 makes your code simple and powerful

Recently, PHP8 was officially released, and the match expression added in the new version has become a hot topic among developers. The match statement can make our PHP code more concise and powerful. This article will introduce you to the usage and advantages of match expressions.

1. What is the match expression?

The match expression is a new language structure in PHP8, similar to the switch statement. Its main function is to select a matching condition from multiple possible situations.

The form of the match statement is as follows:

match ($x) {
    value1 => statement1,
    value2 => statement2,
    value3 => statement3,
    ...
    default => default_statement
}

Among them, $x is the value of the expression, value1, value2, value3, etc. are possible matching values, while statement1, statement2, statement3, etc. correspond to The statement is executed for each matching case.

Different from the switch statement, the match statement does not need to write break in every case, and the matching value can be any expression or variable.

2. Advantages of match expressions

1. More expressive

Before PHP8, we usually used if-else statements to make conditional judgments. But a large number of nested and complex redundant codes make the code increasingly difficult to understand. The match statement can significantly improve the readability and maintainability of the code.

2. More secure

The match expression uses the strict AND (===) comparison operator, which means it is safer. Because it does not involve weak type conversion, it avoids some implicit errors.

3. More efficient

In PHP8, the underlying implementation of the match statement is the construction and search of the hash table. Compared to if-else statements, match executes faster and therefore improves the performance of PHP.

3. Application scenarios of match expressions

So, in which scenarios should match expressions be used? Here are a few examples to help you understand better.

1. Filter array

Use the match statement to easily filter the elements in the array, such as retaining only certain elements. The code is as follows:

$filtered = array_filter($array, fn($value) => match ($value) {
    'apple', 'orange' => true,
    default => false,
});

2. Multiple matching conditions

The match expression can easily handle multiple matching conditions, such as selecting the first even number among 1, 2, 4, and 6 . The code is as follows:

$even = match (true) {
    ($value % 2 == 0 && $value > 0) => $value,
    ($value % 2 == 0 && $value < 0) => -$value,
    ($value % 2 == 1 && $value > 0) => $value + 1,
    ($value % 2 == -1 && $value < 0) => -$value - 1,
    default => 0,
};

3. Language localization

match expressions can be used in language localization, such as returning the corresponding language version according to the user's locale. The code is as follows:

$localized = match ($locale) {
    'en_US', 'en_GB' => 'Hello',
    'fr_FR', 'fr_CA' => 'Bonjour',
    'zh_CN', 'zh_TW' => '你好',
    default => 'Hello',
};

4. Summary

The addition of match expressions in PHP8 can help us write simple and powerful code, greatly improving the readability and maintainability of the code. sex. Moreover, match expressions are safer and more efficient than if-else statements.

In actual development, we can flexibly use match expressions according to different application scenarios to simplify the code and improve efficiency.

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