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- c# - What does null! statement mean? - Stack Overflow
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 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?
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 == null) From operator overloading: A user-defined type can overload a predefined C# operator That is, a type can provide the custom implementation of an operation in case one or both of the operands are of that
- sql - Not equal lt; gt; != operator on NULL - Stack Overflow
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 has no value Hence, SQL has special IS NULL and IS NOT NULL predicates for dealing with NULL
- What is the difference between null and undefined in JavaScript?
The null value is a primitive value that represents the null, empty, or non-existent reference When you declare a variable through var and do not give it a value, it will have the value undefined
- What is the purpose of null? - Stack Overflow
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 comprehensive type system for references in an object oriented language (ALGOL W) My goal was to ensure that all use of references should be absolutely safe, with checking performed automatically by the compiler But I
- 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: #define
- 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 between null and undefined
- 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 falsy values:
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