php中的函数式编程

Question

So I've been writing this class in php (first timer) that has a function that returns a function based on a parameter and it looks something like this:

$f=function($a){
    return function($b){
        return $a.$b;
    };
};

echo $f('a')('b');

but I can't figure out why it doesn't do what I want. Does anyone know the best way to do this?

Basically I need to write a function that takes a string ($type) and writes a function that takes some other strings and turns them into a html input like so:

public static function InputFormat($t){
    return function ($f, $p, $e){
        return 
            "<div class='inputformat' id='".$f."'>".
                "<ul>".
                    "<li id='namefield'>".$f."</li>".
                    "<li id='input'><input name='".$f."' type='".$t."' value='".$p."'></li>".
                    "<li id='error'>".$e."</li>".
                "<ul>".
            "</div>";
    };
}

Answer 1

First, your function does not look good.

You function should look so:

$f = function($a){
   return function ($a) use ($b) {
            return $a.$b;
         };
};

Second: you can't call your function like $f('a')('b');. You call your function this way:

$f2 = $f('a');
echo $f2('b');

This is how closure work in php!

I hope this will help you. Ask me if you have questions.