Basic theory for 'C' Language
(Page : 1)Basic Definitions :
1. Tokens in C
* C tokens are the basic
buildings blocks in C language which are constructed together to write a C
program.
* Each and every smallest individual units in a C
program are known as C tokens.
*A token is either a keyword, an identifier, a constant, a string literal, or a symbol.
Types of tokens in 'C' :
Identifiers ( eg: main, total ),
Constants ( eg: 10, 20 ),
Strings ( eg: “total”, “hello” ),
Special symbols ( eg: (), {} ),
Operators ( eg: +, /,-,* )
For example, the following C statement consists of five tokens:
printf ("My first c program \n");
The individual tokens are:
printf
(
"My first c program \n"
)
;
2. Why Semicolons ( ; ) are used
In C program, the semicolon is a statement terminator. That is, each individual statement
must be ended with a semicolon. It indicates the end of one logical entity and while compiling the compiler considers next line after it encounters semicolon.
For example, following are two different statements:
printf ("My first C Program \n");
return 0;
3. Comments in 'C'
Comments are helping text in your C program, they are indented for human reading and they are ignored by the compiler.
3.1 They start with "/ * " and terminates with the characters " */ " as shown below:
/* My first c program */
3.2 for commenting a line only we use //
eg: // thec-language.blogspot.com
the difference between the two is that in 1st one the whole lines or para within /* */ is considered as comment whereas in the second one if you put // before a line in program only that line will be considered as a comment.
