Top "Null" questions

php is null or empty?

I have a question regarding NULL in PHP: $a = ''; if($a == NULL) { echo 'is null'; } Why do I see …

php null

Not equal <> != operator on NULL

Could someone please explain the following behavior in SQL? SELECT * FROM MyTable WHERE MyColumn != NULL (0 Results) SELECT * FROM MyTable WHERE …

sql sql-server tsql null

Difference between null and empty ("") Java String

What is the difference between null and the "" (empty string)? I have written some simple code: String a = ""; String b = …

java string null equals referenceequals

MySQL: selecting rows where a column is null

I'm having a problem where when I try to select the rows that have a NULL for a certain column, …

mysql null

How to check null objects in jQuery

I'm using jQuery and I want to check the existence of an element in my page. I have written following …

javascript jquery dom object null

What is the difference between null and undefined in JavaScript?

I want to know what the difference is between null and undefined in JavaScript.

javascript null undefined

Filtering for empty or NULL names in a queryset

I have first_name, last_name & alias (optional) which I need to search for. So, I need a query …

django django-models django-queryset filter null

How to check a string against null in java?

How can I check a string against null in java? I am using stringname.equalsignorecase(null) but it's not working.

java string null

How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly?

I have a dataframe with ~300K rows and ~40 columns. I want to find out if any rows contain null values …

python pandas null nan

Checking for NULL pointer in C/C++

In a recent code review, a contributor is trying to enforce that all NULL checks on pointers be performed in …

c++ c if-statement null coding-style