将Php-array发送给JavaScript-variable.获取SyntaxError: Unexpected令牌

我试图将数组从php发送到我的Javascript中的变量，但我得到一个Unexpected token :-error。

我的JavaScript代码行，在php-document的script-tag中包含:

arrayProductTypesFromDB = <?php echo json_encode(getProductTypes()); ?>;

上面调用的php函数代码:

function getProductTypes(){
        //here I have code which fetches from database and makes $result into an stdClass-object. This works fine, as I can successfully use that object within php
        foreach ($result as $r) {
            echo 'id: ' . $r->id . ", type: " . $r->type_name . ", ins: " . $r->nbr_ins . "<br>"; //this works fine
        }
        $array = json_decode(json_encode($result), true); //this turns it into an array, and this works fine within php
        echo $array[0]['id']; //no problem here
        return $array; //this is what I send to JavaScript.. and it doesn't work.
    }