C programming enumeration
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Enumerations allow defining a user-defined data type consisting of integral constants. An enum defines a set of named constants and optionally assigns them values. By default, the first constant is 0 and subsequent constants are integers incrementing by 1. Enumerated types are useful for working with sets of related flag values that can be logically combined. They provide type safety and efficiency compared to using integer constants directly.
C programming enumeration
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- 2. • An enumeration is a user-defined data type that consists of integral constants. To define an enumeration, keyword enum is used. • enum flag { const1, const2, ..., constN }; • Here, name of the enumeration is flag. • And, const1, const2,...., constN are values of type flag. • By default, const1 is 0, const2 is 1 and so on. You can change default values of enum elements during declaration (if necessary). • // Changing default values of enum • enum suit { club = 0, diamonds = 10, hearts = 20, spades = 3 }; 2
- 3. Enumerated Type Declaration • When you create an enumerated type, only blueprint for the variable is created. Here's how you can create variables of enum type. enum boolean { false, true }; enum boolean check; • Here, a variable check of type enum boolean is created. • Here is another way to declare same check variable using different syntax. enum boolean { false, true } check; 3
- 5. Why enums are used in C programming? • Enum variable takes only one value out of many possible values. Example to demonstrate it, This makes enum a good choice to work with flags. 5
- 6. • It's because the size of an integer is 4 bytes. • This makes enum a good choice to work with flags. • You can accomplish the same task using structures. However, working with enums gives you efficiency along with flexibility. 6
- 7. How to use enums for flags? • Suppose you are designing a button for Windows application. You can set flags ITALICS, BOLD and UNDERLINE to work with text. • here is a reason why all the integral constants are power of 2 in above pseudocode. 7
- 8. • Since, the integral constants are power of 2, you can combine two or more flags at once without overlapping using bitwise OR | operator. This allows you to choose two or more flags at once. For example, 8
- 9. • When the output is 5, you always know that bold and underline is used. • Also, you can add flag to your requirements. 9
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