What is the difference between NULL, '\0' and 0? - Stack Overflow
In C, there appear to be differences between various values of zero -- NULL, NUL and 0. I know that the ASCII character '0' evaluates to 48 or 0x30. The NULL pointer is usually defined as: …
c# - What does null! statement mean? - Stack Overflow
Feb 16, 2019 · Basically, null! applies the ! operator to the value null. This overrides the nullability of the value null to non-nullable, telling the compiler that null is a "non-null" type.
What is the difference between "is not null" and "!= null"?
Sep 21, 2021 · The only difference (besides the syntax) is, that the compiler guarantees that no user-overloaded operator is called when using is not null instead of != null (or is null instead of …
sql - Not equal <> != operator on NULL - Stack Overflow
Oct 9, 2014 · 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 …
How do I check for null values in JavaScript? - Stack Overflow
Jan 4, 2024 · And then == null does a perfect job, because it covers exactly those 2 values. (i.e. == null is equivalent to === null && === undefined) In exceptional cases you do want a clear …
SQL is null and = null - Stack Overflow
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 …
What is null in Java? - Stack Overflow
Apr 25, 2010 · The null reference can always be cast to any reference type. In practice, the programmer can ignore the null type and just pretend that null is merely a special literal that …
Why does NULL = NULL evaluate to false in SQL server
Dec 3, 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 …
SQL Server: Null VS Empty String - Stack Overflow
Apr 11, 2011 · How are the NULL and Empty Varchar values stored in SQL Server. And in case I have no user entry for a string field on my UI, should I store a NULL or a '' ?
Java null check why use == instead of .equals() - Stack Overflow
Feb 5, 2012 · In Java I am told that when doing a null check one should use == instead of .equals(). What are the reasons for this?