$ _post ['value']存在但是当我用空检查它时它返回false

Question

I have a post-variable that has to be checked whether it is empty or not. I look at the value of the variable like this:

print_r($_POST['arrayId']);

and it prints the expected value. However if I do this:

if(!empty($_POST['arrayId'])) {
    // some stuff
} else {
    echo "f";
}

f is printed, and the code that should be executed isn't. How is this possible?

Answer 1

do this instead, it will check if the key is present in the post array, regardless of the value. also works for NULL, false, 0 and any other values which are treated as "empty" values...

if(array_key_exists('arrayId', $_POST)) {
    // some stuff
} else {
    echo "f";
}