Dec 4, 2009 · The expression "NULL = NULL" evaluates to NULL, but is actually invalid in SQL; yet ORDER BY treats NULLs as equal (whatever they precede or follow "regular" values is left …

Mar 6, 2012 · The reasoning is that a null means "unknown", so the result of any comparison to a null is also "unknown". So you'll get no hit on rows by coding where my_column = null. SQL …

Sep 21, 2021 · The main difference between e != null and e is not null is the way the the compiler executes the comparison. Microsoft: "The compiler guarantees that no user-overloaded …

How can I check for null values in JavaScript? I wrote the code below but it didn't work.

Apr 14, 2011 · 135 NULL has no value, and so cannot be compared using the scalar value operators. In other words, no value can ever be equal to (or not equal to) NULL because NULL …

Jul 20, 2010 · How do I refer to the null object in Python?

Sep 6, 2013 · The operators for Nullable<T> are so-called "lifted" operators]; the c# compiler takes the operators available for T and applies a set of pre-defined rules; for example, with +, …

In short, when you care that let a variable assigned from a possible null undefined source, and you wish to provide a default value to the variable, use the nullish coalescing operator ??.

Feb 25, 2009 · Null: The Billion Dollar Mistake. Tony Hoare: I call it my billion-dollar mistake. It was the invention of the null reference in 1965. At that time, I was designing the first …

96 Checking null with normal equality will also return true for undefined. if (window.variable == null) alert('variable is null or undefined');