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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
- 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 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
- javascript - Why is null an object and whats the difference between . . .
null is a primitive value that represents the intentional absence of an object value null is also a one-of-a-kind type in the ECMAScript specification null in JavaScript was designed with a view to enable interoperability with Java, both from a "look" perspective, and from a programmatic perspective (eg the LiveConnect Java JS bridge planned
- SQL is null and = null - Stack Overflow
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 provides the special syntax for testing if a column is null, via is null and is not null, which is a special condition to test for a null (or not a null)
- Java null check why use == instead of . equals() - Stack Overflow
In Java I am told that when doing a null check one should use == instead of equals() What are the reasons for this?
- 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
- 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
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