c# - What does null! statement mean? - Stack Overflow
Feb 16, 2019 · It can be used on a type to control Nullability, it is then called the "Null Forgiving Operator". Basically, null! applies the ! operator to the value null. This overrides the nullability …
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 …
What is the purpose of null? - Stack Overflow
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 …
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: …
How can I check for an undefined or null variable in JavaScript?
The title of this bug says "check for undefined or null", but the question itself checks for undeclared or null.
sql - Not equal <> != operator on NULL - Stack Overflow
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 …
When should I use ?? (nullish coalescing) vs || (logical OR)?
The null (ish) coalescing operator only works with null and undefined. So, use the null (ish) coalescing operator when you don't want those values but you will otherwise accept other …
What are the differences between Null, Zero and Blank in SQL?
Sep 6, 2017 · Comparing NULL with anything yields a NULL. NULL is part of trinary logic: TRUE, FALSE, and NULL. -- These are all NULL. select NULL > -1, NULL < -1, NULL = NULL, NULL …
How do I check for null values in JavaScript? - Stack Overflow
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 distinction …
What exactly is meant by "dereferencing a NULL pointer"?
In other words, a null pointer is a pointer of any type pointing at a well-defined "nowhere". Any pointer can turn into a null pointer when it is assigned a null pointer constant. The standard …