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Fundamentals of Data Structures
Notes 1.2.3 C Character Types
C uses char type to store characters and letters. However, the char type is integer type because
underneath C stores integer numbers instead of characters.
In order to represent characters, the computer has to map each integer with a corresponding
character using a numerical code. The most common numerical code is ASCII, which stands for
American Standard Code for Information Interchange. Table 1.5 illustrates the ASCII code:
Table 1.5: ASCII Code Chart
Example: The integer number 65 represents a character A in upper case.
In C, the char type has 1-byte unit of memory so it is more than enough to hold the ASCII codes.
Besides ASCII code, there are various numerical codes available such as extended ASCII codes.
Unfortunately, many character sets have more than 127 even 255 values. Therefore, to fulfill
those needs, the Unicode was created to represent various available character sets. Unicode
currently has over 40,000 characters.
1.2.4 C Enum
Enum defines enumeration types, to enhance your code readability.
C provides developers with special types called enumerated types or enum to declare symbolic
names that represent integer constants. Its main purpose is to enhance the readability of the
code. An enumeration consists of a group of symbolic integers.
Example: We can declare an enumeration for colors as follows:
enum color {red, green, blue};
In the example given above:
enum is the keyword to declare a new enumeration type
color is the tag name that you can use later as a type name.
!
Caution The tag name must be unique within its scope. This tag name is also optional so
you can omit it.
Inside the curly brackets {} is a set of named integers. This set is also known as enumeration
constants, enumeration sets, enumerators or just members.
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