Sams Teach Yourself C in 21 Days

• The size of a charis one byte.


• The size of a shortis less than or equal to the size of an int.


• The size of an intis less than or equal to the size of a long.


• The size of an unsignedis equal to the size of an int.


• The size of a floatis less than or equal to the size of a double.

48 Day 3

Table 3.2 listed the common keyword used to identify the different variable

types. The following table (Table 3.3) lists the full name of each of the data

types.

As you can see from this table, shortandlongtypes are really just variations

on the inttype. Most programmers don’t use the full name of the variable

types, rather thy use the shorter version.

Note

TABLE3.3 Full names of data types

Full name commonly used keyword

char signed char

short signed short int

int signed int

long signed long int

long long signed long long int

unsigned char unsigned char

unsigned short unsigned short int

unsigned int unsigned int

unsigned long unsigned long int

unsigned long long unsigned long long int

Variable Declarations ......................................................................................

Before you can use a variable in a C program, it must be declared. A variable declaration

tells the compiler the name and type of a variable. The declaration may also initialize the

variable to a specific value. If your program attempts to use a variable that hasn’t been

declared, the compiler generates an error message. A variable declaration has the follow-

ing form:

typename varname;

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