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C# has and allows pointers to selected types (some primitives, enums, strings, pointers, and even arrays and structs if they contain only types that can be pointed [14]) in unsafe context: methods and codeblock marked unsafe. These are syntactically the same as pointers in C and C++. However, runtime-checking is disabled inside unsafe blocks.
The EnumSet class implements a Set of enum values; it is implemented as a bit array, which makes it very compact and as efficient as explicit bit manipulation, but safer. The EnumMap class implements a Map of enum values to object. It is implemented as an array, with the integer value of the enum value serving as the index.
A lookup table, which contains, as keys, the case values and, as values, the part under the case statement. (In some languages, only actual data types are allowed as values in the lookup table. In other languages, it is also possible to assign functions as lookup table values, gaining the same flexibility as a real switch statement.
In C# you have to write three additional instructions: Declare a variable, copy the property value into the variable and copy the variable back to the property after the method call. Enums can be defined inside interfaces; Case statements may contain inequality expressions, like Is >= 3. (in C# this can be mimicked by nested Else and If statements)
The following example of a SELECT query returns a list of expensive books. The query retrieves all rows from the Book table in which the price column contains a value greater than 100.00. The result is sorted in ascending order by title. The asterisk (*) in the select list indicates that all columns of the Book table should be included in the ...
Examples of reference types are object (the ultimate base class for all other C# classes), System. String (a string of Unicode characters), and System. Array (a base class for all C# arrays). Both type categories are extensible with user-defined types.
For example, a precondition—an assertion placed at the beginning of a section of code—determines the set of states under which the programmer expects the code to execute. A postcondition—placed at the end—describes the expected state at the end of execution. For example: x > 0 { x++ } x > 1.
Enumerations in C# are implicitly derived from the Enum type that again is a value type derivative. The value set of a C# enumeration is defined by the underlying type that can be a signed or unsigned integer type of 8, 16, 32 or 64 bits. The enumeration definition defines names for the selected integer values.