Книга: Advanced PIC Microcontroller Projects in C

3.1.7 Variable Types

3.1.7 Variable Types

The mikroC language supports the variable types shown in Table 3.2. Examples of variables are given in this section.

Table 3.2: mikroC variable types

The variables (unsigned) char, or unsigned short (int), are 8-bit unsigned variables with a range of 0 to 255. In the following example two 8-bit variables named total and sum are created, and sum is assigned decimal value 150:

unsigned char total, sum;
sum = 150;

or

char total, sum;
sum = 150;

Variables can be assigned values during their declaration. Thus, the above statements can also be written as:

char total, sum = 150;

The variables signed char, or (signed) short (int), are 8-bit signed character variables with a range of –128 to +127. In the following example a signed 8-bit variable named counter is created with a value of –50:

signed char counter = -50;

or

short counter = -50;

or

short int counter = -50;

Variables called (signed) int are 16-bit variables with a range –32768 to +32767. In the following example a signed integer named Big is created:

int Big;

Variables called (unsigned) int are 16-bit unsigned variables with a range 0 to 65535. In the following example an unsigned 16-bit variable named count is created and is assigned value 12000:

unsigned int count = 12000;

Variables called (signed) long (int) are 32 bits long with a range –2147483648 to +2147483647. An example is:

signed long LargeNumber;

Variables called (unsigned) long (int) are 32-bit unsigned variables having the range 0 to 4294967295. An example is:

unsigned long VeryLargeNumber;

The variables called float or double or long double, are floating point variables implemented in mikroC using the Microchip AN575 32-bit format, which is IEEE 754 compliant. Floating point numbers range from ±1.17549435082E-38 to ±6.80564774407E38. In the following example, a floating point variable named area is created and assigned the value 12.235:

float area;
area = 12.235;

To avoid confusion during program development, specifying the sign of the variable (signed or unsigned) as well as the type of variable is recommended. For example, use unsigned char instead of char only, and unsigned int instead of unsigned only.

In this book we are using the following mikroC data types, which are easy to remember and also compatible with most other C compilers:

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