在循环之前检查（使用PHP）变量的正确方法？

Before looping through a variable (supposed to be an array) I would make the following test:

if(
        !empty($arrJobs)    &&
        is_array($arrJobs)  &&
        count($arrJobs)
){
foreach ($arrJobs as $item) {
  //loop tasks
}
}

I've seen also using if(sizeof($arrJobs)>0) but in case $arrJobs isa integer (I can't trust the input) it would be through and I will try looping through a integer...weird.

Is there a more concise and comprehensive way to perform this test before looping through the array?

You don't need to check anything but is_array: if it's empty, PHP simply won't loop.

Moreover a suggestion: if those if had sense (not that case, but is helpful for this explanation) you should split with "early exit" (as coding style because it improves readability)

if (empty($arrJobs)) {
 return;
}

if (!is_array($arrJobs)) {
 return;
}

if (count($arrJobs)) {
 return;
}

It is IMPORTANT to check if you're looping an ARRAY to FOREACH or else PHP will give you errors ... FOREACH expects parameter to be ARRAY..

You can use IS_ARRAY .. I believe that would be enough.

But checking it if empty would be VERY GOOD Practice... I'm using COUNT() to check if an ARRAY is empty.