In mysqli, what is the simplest way to determine whether the result set is empty?

In mysqli, the easiest way to determine whether a result set is empty is. I found that the result set is not empty. this is generally the case: if ($ result-& gt; num_rows & gt; 0) & nbsp ;{& nbsp ;}but cannot be written like this: if ($ result) I use var_dump ($ result); output, the result is & n. In mysqli, what is the simplest method to determine whether the result set is null?
I found that the judgment result set is not empty and should be written as follows:

If ($ result-> num_rows> 0 ){}

But cannot write it like this:

If ($ result)

I use var_dump ($ result); output, the result is


Object (mysqli_result) #2 (0 ){}

It can be seen that when the result set is empty, $ result is an empty object with no members. I read the book that when the object is converted to a Boolean object, the object without members will be converted to false, otherwise, convert it to true. why is this empty object not converted to false.

I also want to ask if mysql and PDO have to judge that the number of records attribute is 0 if the result set is null. Share To: num_rows> 0 )? {?} But you cannot write it like this: if ($ result) I use var_dump ($ result); output, close... 'data-pics = ''>
------ Solution --------------------
Yes. in mysql and PDO, if the result set is null, the number of records must be 0.