我可以使用PHP匿名函数作为参数，而无需将函数赋值给变量吗？

Question

Does PHP allow the use of an anonymous function as one of the arguments during concatenation?

If so, what is the proper syntax?

For example, here's an example of what I want to get to work:

$final_text = $some_initial_string . function ($array_of_strings)
{
    $out = '';
    foreach ($array_of_strings as $this_particular_string)
    {
        $out .= $this_particular_string;
    }
    return $out;
};

Answer 1

Note: the below is expected to work for PHP Version 7.x but does not work on PHP Version 5.6 (For 5.6, first assign the anonymous function to a variable)

/*
 * Strings before & after
 */
$table_heading_text = "HEADING";
$table_bottom_text = "BOTTOM";

/*
 * Use the function this way
 */
echo $table_heading_text . (function (array $array_of_strings)
{
    $out = '';
    foreach ($array_of_strings as $this_particular_string)
    {
        $out .= $this_particular_string;
    }
    return $out;
})(array(
    "hi",
    "mom"
)) . $table_bottom_text;

In short ...

1. function must return some value that can be converted to text
2. function definition must be enclosed in parenthesis ( ... )
3. Don't forget to have calling arguments after the function definition

Examples:

echo "BEFORE" . (function ($x){return $x;})(" - MIDDLE - ") . "AFTER";
echo "BEFORE" . (function (){return " - MIDDLE - ";})() . "AFTER";

Also, using implode() may be better for this particular task.