Question

I have a body function and a function called within the first one.

As can be seen below I don’t change the parameters name while using in the second function.

Is it necessary to change the params names for use inside _display_bar();? What are the side effects if I don’t?

    function main_func($form, &$form_state, $key, $code) {
    $output = '';
    ...
    $output .= _display_navbar($trans, $status_names);

    return $output
    }

    function _display_navbar($trans, $status_names) {
     $trans = 'bla';
     $status_names = 'another bla';
   $bar = $trans . ':' .$status_names;
     return $bar;
    };

Answer 1

It actually does not matter. But you better should not have the same names – it is confusing. Let me give you an example. $s will have 3 after the first function call to sum; 7 after the second function call to sum. The parameters did not have the same name as the function parameter names.

To answer your question fully – there are absolutely no side effects.

function main()
{
    $a = 1;
    $b = 2;
    $s = sum($a, $b);

    $d = 3;
    $e = 4;
    $s = sum($d, $e);
}

function sum($first, $second) 
{
    $ret = $first + $second;
    return $ret;
}