str_replace（）无效

for the first time I encounter such a problem. It works;

function translate($google) {
$en = array(
    "Mother", "Father"
 );
 $de= array(
    "Mutter", "Vater" 
 );
$s = str_replace($en,$de,$google);
return $s;}

But this does not work

$en = array(
        "Mother", "Father"
     );
     $de= array(
        "Mutter", "Vater" 
     );
function translate($google, $en, $de) {
    $s = str_replace($en,$de,$google);
    return $s;
}

where do i make mistakes?

Last time I'll use it like this;

echo translate(fonkfonk(str_replace(array("
","","\t"),array("‌​","",""),file_get_co‌​ntents($cache))));

Your problem is that you're not providing the values of $en and $de to your function when calling it.

$en = array("Mother", "Father");
$de = array("Mutter", "Vater");
function translate($google, $en, $de) {
    $s = str_replace($en,$de,$google);
    return $s;
}

echo translate(fonkfonk(.....)); // error because translate() does not know what
                                 // $en and $de are supposed to be

You are only providing the result of the fonkfonk() function as the first argument ($google) and not providing a second and third argument.

What you should do is either provide the values of $en and $de in your function call, or import them when you define the function:

function translate($google, $en, $de) {
    $s = str_replace($en,$de,$google);
    return $s;
}

$en = array("Mother", "Father");
$de = array("Mutter", "Vater");
echo translate(fonkfonk(.....), $en, $de);

Or:

$en = array("Mother", "Father");
$de = array("Mutter", "Vater");
function translate($google) use ($en, $de) {
    $s = str_replace($en,$de,$google);
    return $s;
}

echo translate(fonkfonk(.....));