How can closures be used to address the issue of passing additional variables to a callback function in PHP?

When passing a callback function in PHP, it can be challenging to pass additional variables to the callback function without modifying its signature. Closures can be used to capture and store additional variables within the function scope, allowing them to be accessed when the callback is executed. 

// Define a closure that captures additional variables
$additionalVariable = 'Hello';
$callback = function($value) use ($additionalVariable) {
    echo $value . ' ' . $additionalVariable;
};

// Pass the closure as a callback function
function someFunction($callback) {
    $callback('World');
}

someFunction($callback); // Output: World Hello

Keywords

closures callback function additional variables PHP passing

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