我如何检查声明数组是否为空？

I have an array called tagcat , like so

$tagcat = array();

....
while ( $stmt->fetch() ) {
    $tagcat[$tagid] = array('tagname'=>$tagname, 'taghref'=>$taghref);
}

Using print_r($tagcat) i get the following result set

   Array ( [] => Array ( [tagname] => [taghref] => ) )

Using var_dump($tagcat), i get

array(1) { [""]=> array(2) { ["tagname"]=> NULL ["taghref"]=> NULL } }

In php, i want to check if the array is empty. But when using the following conditions, it always finds something in the array, which is not true!

if ( isset($tagcat) ) {
    echo 'array is NOT empty';
} else {
    echo 'EMPTY!!!';
}

if ( !empty($tagcat) ) {
    echo 'array is NOT empty';
} else {
    echo 'EMPTY!!!';
}

How do i check if the array is empty?

Use array_filter

if(!array_filter($array)) {
  echo "Array is empty";
}

This was to check for the single array. For multi-dimensional array in your case. I think this should work:

$empty = 0;
foreach ($array as $val) {
  if(!array_filter($val)) {
    $empty = 1;
  }
}

if ($empty) {
  echo "Array is Empty";
}

If no callback is supplied, all entries of $array equal to FALSE will be removed.

With this it only returns the value which are not empty. See more in the docs example Example #2 array_filter() without callback

If you need to check if there are ANY elements in the array

if (!empty($tagcat) ) { //its $tagcat, not tagcat
    echo 'array is NOT empty';
} else {
    echo 'EMPTY!!!';
}

Also, if you need to empty the values before checking

foreach ($tagcat as $cat => $value) {
    if (empty($value)) {
       unset($tagcat[$cat]);
    }
}
if (empty($tagcat)) {
   //empty array
}

Hope it helps

EDIT: I see that you have edited your $tagcat var. So, validate with vardump($tagcat) your result.

if (empty($array)) {
 // array is empty.
 }

if you want remove empty elements try this:

foreach ($array as $key => $value) {
  if (empty($value)) {
     unset($array[$key]);
  }
}