你认为foreach（（数组）$ foo为$ bar）代码味道？

Question

Do you consider this a code smell?

foreach((array)$foo as $bar)
{
    $bar->doStuff();
}

Should i use that instead?

if (isset($foo) && is_array($foo))
{
    foreach($foo as $bar)
    {
        $bar->doStuff();
    }
}

Any other good practices to cover not set variables and assert an array?

Answer 1

They're both code smells. The second one is just evading all the error messages, kind of like turning off the fire alarm before you set your kitchen on fire. Both of those tell you that you have no idea what's in the variable $foo or if it's even been defined in the code above. You need to go back up through the code and find out exactly what's going on with $foo.

If it was my code, $foo would probably be always defined either as an array, or else false to indicate the array isn't needed:

if(do_we_need_an_array())
  $foo = function_returning_an_array();
else
  $foo = false;

[...snip...]

if($foo)
  foreach($foo as $f) { ... }