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How to create a PHP function that accepts a callback and arguments for it?
How to create a PHP function that accepts a callback and arguments for it?
Jul 07, 2025 am 02:50 AM
To create a PHP function that accepts callbacks and their parameters, 1. Use call_user_func_array() to call dynamic callbacks and pass parameter arrays; 2. Verify whether the callback is legal through is_callable() to avoid invalid calls; 3. Support closures, object methods and static methods to improve flexibility. For example: define the run_callback($callback, $args) function, first check the validity of the callback, and then use call_user_func_array() to execute, support multiple calling forms such as functions, methods and closures, and can pass in parameter arrays to ensure that the system is scalable and safe.
Sure, here's how to create a PHP function that accepts a callback and its arguments.
Let's say you want a reusable function that runs any callback someone passes in — maybe for flexibility or triggering different behaviors depending on the situation. The trick is making sure your function can accept both the callback and any arguments it needs.
1. Use call_user_func_array() for dynamic callbacks
PHP has a built-in function called call_user_func_array() which lets you call a callback with an array of arguments. It's perfect when you don't know ahead of time what the callback will be or how many arguments it needs.
Here's a basic structure:
function run_callback($callback, $args = []) {
return call_user_func_array($callback, $args);
}You'd use it like this:
function greet($name) {
echo "Hello, $name!";
}
run_callback('greet', ['John']);
// Output: Hello, John!This works with:
- Regular functions
- Static methods (
['ClassName', 'methodName']) - Object methods (
[$object, 'methodName']) - Anonymous functions (closures)
2. Validate the callback before calling it
Before trying to execute a callback, it's a good idea to check if it's actually callable. You can use is_callable() for that.
Update your function like this:
function run_callback($callback, $args = []) {
if (!is_callable($callback)) {
throw new InvalidArgumentException('The provided callback is not callable.');
}
return call_user_func_array($callback, $args);
}That way, if someone accidentally passes something that can't be used as a callback — like a string that doesn't match a function name — you'll get a clear error instead of PHP failing silently.
3. Pass extra parameters or chain logic easy
Since the callback can be anything callable, you can also wrap things up in closings for more control. For example:
run_callback(function() {
echo "This runs without needing external args.";
});Or if you need to pass values ??dynamically:
$data = ['user' => 'Alice', 'role' => 'Admin'];
run_callback(function($data) {
echo "{$data['user']} is a {$data['role']}";
}, [$data]);This makes it easy to build flexible systems — like event hooks, filters, or middleware layers — where the actual behavior can change based on context.
That's basically it.
It's not complicated, but the key points are using call_user_func_array() to handle variable arguments, checking with is_callable() for safety, and keeping the design open for closings or object methods.
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