Question

In php 5.3, when you create an anonymous function, can you set the default values?

Like in a normal functon you do

function tim($a=123){

}

where 123 is the default value for $a. What abut in anonymous functions?

UPDATE

I’m having trouble with it in this context:

//$data is an object;
$data->title = 'test';
add_filter('title',function($current, $new = $data->title ){ return $new; });

produces “unexpected T_VARIABLE”

works fine without the $data->title bit, but I really want to pass this in…

add_filter('title',function($current, $new = 'some-title' ){ return $new; });

I’m adding a filter in WordPress. Works fine if I explicitly set it, but I want to pull it from another variable. Is that possible?

Answer 1

$ php -r '$foo = function($a = 123){echo $a, PHP_EOL;};$foo(1);$foo();'
1
123

So that’s a yes

Update

You can only assign simple values to argument defaults. From the manual

The default value must be a constant expression, not (for example) a variable, a class member or a function call.

Try passing the external variable via the use keyword

add_filter('title', function($current, $new = null) use ($data) {
    if (null === $new) {
        $new = $data->title;
    }
    return $new;
});