I want to do something like this:
class Cls { function fun($php) { return 'The rain in Spain.'; } } $ar = array(1,2,3); $instance = new Cls(); print_r(array_map('$instance->fun', $ar)); // ^ this won't work
but the first argument to array_map is supposed to be the name of the function. I want to avoid writing a wrapper function around $instance->fun, but it doesn't seem like that's possible. Is that true?
Yes, you can have callbacks to methods, like this:
array_map(array($instance, 'fun'), $ar)
see the callback type in PHP's manual for more info
Metronom
You can also use
array_map('Class::method', $array)
syntax.
lijinma
Actually, you need to know the definition of Callback, please kindly refer to the following code:
<?php
// An example callback function
function my_callback_function() {
echo 'hello world!';
}
// An example callback method
class MyClass {
static function myCallbackMethod() {
echo 'Hello World!';
}
}
$myArray = [1, 2, 3, 4];
// Type 1: Simple callback
array_map('my_callback_function', $myArray);
// Type 2: Static class method call
array_map(array('MyClass', 'myCallbackMethod'), $myArray);
// Type 3: Object method call
$obj = new MyClass();
array_map(array($obj, 'myCallbackMethod'), $myArray);
// Type 4: Static class method call (As of PHP 5.2.3)
array_map('MyClass::myCallbackMethod', $myArray);
// Type 5: Relative static class method call (As of PHP 5.3.0)
class A {
public static function who() {
echo "A\n";
}
}
class B extends A {
public static function who() {
echo "B\n";
}
}
array_map(array('B', 'parent::who'), $myArray); // A
?>
来源:https://stackoverflow.com/questions/1077491/can-a-method-be-used-as-an-array-map-function