Tag: anonymous-function

php initialize “use” variable for anonymous function / closure

Is there a neat way to initialize a variable used in a closure? …does not work An example use case is for array_reduce where we might want to count the array elements… This will work – declaring $count by reference and incrementing from null will not yield an error – but I don’t think this is “good practice”. Answer You

What exactly is the difference between an anonymous function and a static anonymous function in PHP?

anonymous-function callback php static

Basically the purpose of the static keyword is totally clear to me, the PHP docs only explain the purpose of the keyword in the context of classes. I noticed one of my IDE plugins suggesting me that I should declare many of my callback functions as static. Without static: With static: For the result it does not make a difference,

Rewriting an anonymous function in php 7.4

anonymous-function arrow-functions closures php php-7.4

There is the following anonymous recursive function: I try to rewrite to version 7.4, but there is an error, please tell me what I’m missing? Notice: Undefined variable: f Fatal error: Uncaught Error: Function name must be a string Answer Just like Barmar said, you can’t use $f from the outside scope, because when the implicit binding takes place $f

PHP 7.2 Function create_function() is deprecated

anonymous-function closures php

I have used create_function() in my application below. But for PHP 7.2.0, create_function() is deprecated. How do I rewrite my code above for PHP 7.2.0? Answer You should be able to use an Anonymous Function (aka Closure) with a call to the parent scoped $delimiter variable, like so:

What is the scope of a PHP function defined within a PHP anonymous function?

anonymous-function function php scope

Question If I do this: 1) Is it legal PHP? And … 2) Is the function lengthTest() in the global namespace, or limited to just the $checkName Closure object? Would it be a private member, then? 3) Can lengthTest() be refereced as a callback method for filter_var_array() like this? 4) Can lengthTest be referenced as a callback function for filter_var_array()

Anonymous functions in WordPress hooks

anonymous-function closures hook php wordpress

WordPress hooks can be used in two ways: using callback function name and appropriate function using anonymous function (closure) Is there any difference for WordPress what way to use? What is prefered way and why? Answer The disadvantage of the anonymous function is that you’re not able to remove the action with remove_action. Important: To remove a hook, the $function_to_remove

Which version of php added anonymous functions

anonymous-function php

In manual there is create_function function and you can pass result from that function to array_map, I thought that that is the only way to have something like anonymous functions and closures, but then I found that I can just put function like in javascript In which version of php I can do this? Was this always there? Answer Closures