3.1.2 Beginning and Ending of a Program
In C language, a program begins with the keywords:
void main()
After this, a curly opening bracket is used to indicate the beginning of the program body. The program is terminated with a closing curly bracket. Thus, as shown in Figure 3.1, the program has the following structure:
void main() {
program body
}
3.1.3 Terminating Program Statements
In C language, all program statements must be terminated with the semicolon (“;”) character; otherwise a compiler error will be generated:
j = 5; // correct
j = 5 // error
3.1.4 White Spaces
White spaces are spaces, blanks, tabs, and newline characters. The C compiler ignores all white spaces. Thus, the following three sequences are identicaclass="underline"
int i; char j;
or
int i;
char j;
or
int i;
char j;
Similarly, the following sequences are identicaclass="underline"
i = j + 2;
or
i = j
+ 2;
3.1.5 Case Sensitivity
In general, C language is case sensitive and variables with lowercase names are different from those with uppercase names. Currently, however, mikroC variables are not case sensitive (although future releases of mikroC may offer case sensitivity) so the following variables are equivalent:
total TOTAL Total ToTal total totaL
The only exception is the identifiers main and interrupt, which must be written in lowercase in mikroC. In this book we are assuming that the variables are case sensitive, for the sake of compatibility with other C compilers, and variables with the same name but different cases are not used.
3.1.6 Variable Names
In C language, variable names can begin with an alphabetical character or with the underscore character. In essence, variable names can include any of the characters a to z and A to Z, the digits 0 to 9, and the underscore character “_”. Each variable name should be unique within the first 31 characters of its name. Variable names can contain uppercase and lowercase characters (see Section 3.1.5), and numeric characters can be used inside a variable name. Examples of valid variable names are:
Sum count sum100 counter i1 UserName
_myName
Some names are reserved for the compiler itself and cannot be used as variable names in a program. Table 3.1 gives a list of these reserved names.
Table 3.1: mikroC reserved names
| asm | enum | signed |
| auto | extern | sizeof |
| break | float | static |
| case | for | struct |
| char | goto | switch |
| const | if | typedef |
| continue | int | union |
| default | long | unsigned |
| do | register | void |
| double | return | volatile |
| else | short | while |
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
| Type | Size (bits) | Range |
|---|---|---|
| unsigned char | 8 | 0 to 255 |
| unsigned short int | 8 | 0 to 255 |
| unsigned int | 16 | 0 to 65535 |
| unsigned long int | 32 | 0 to 4294967295 |
| signed char | 8 | –128 to 127 |
| signed short int | 8 | –128 to 127 |
| signed int | 16 | –32768 to 32767 |
| signed long int | 32 | –2147483648 to 2147483647 |
| float | 32 | ±1.17549435082E-38 to ±6.80564774407E38 |
| double | 32 | ±1.17549435082E-38 to ±6.80564774407E38 |
| long double | 32 | ±1.17549435082E-38 to ±6.80564774407E38 |
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: