English
English
In PHP development, function composition is a common requirement. Linking multiple functions according to certain logic can improve code readability and maintainability. Introduced in PHP 7.4, arrow functions make function composition more concise and intuitive. This article introduces how to use arrow functions with practical code examples.
<span class="fun">$fn = fn($arg1, $arg2, ...) => expression;</span>
The syntax of arrow functions is similar to anonymous functions, but it uses the fn keyword instead of function. Arrow functions can only contain a single expression, and the result of that expression is automatically returned.
$str = ' hello, world! ';
$modify = fn($s) => strtoupper(str_replace(' ', '', $s));
$result = $modify($str);
echo $result; // Output: HELLO,WORLD!In this example, the arrow function $modify removes spaces from the string and converts it to uppercase. The processed result is assigned to $result and then output.
$arr = [' apple ', ' banana ', ' orange '];
$modify = fn($s) => strtoupper(trim($s));
$newArr = array_map($modify, $arr);
print_r($newArr);Here, the arrow function $modify trims spaces and converts each element of an array to uppercase. Using array_map, $modify is applied to every element in $arr, and the results are stored in $newArr.
Arrow functions simplify function definitions and calls, making function composition more intuitive. They eliminate the need for intermediate variables, resulting in cleaner and more readable code. However, arrow functions cannot accept parameters by reference and do not support variable variables or static variables.
PHP arrow functions provide a concise and efficient way to compose functions. By using arrow functions flexibly, developers can optimize code structure, improve readability, and increase development efficiency. The examples in this article provide a foundation for understanding arrow functions and applying them in real-world projects for cleaner and more efficient code.
