Basic Syntax

Basic Syntax

You have seen the basic structure of a C program, so it will be easy to
understand other basic building blocks of the C programming language.

Tokens in C

A C program consists of various tokens and a token is either a keyword, an
identifier, a constant, a string literal, or a symbol. For example, the following C
statement consists of five tokens:

printf("Hello, World! \n"); The individual tokens are: printf ( "Hello, World! \n" ) ;

Semicolons

In a 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.
Given below are two different statements:

printf("Hello, World! \n"); return 0;

Comments

Comments are like helping text in your C program and they are ignored by the
compiler. They start with /* and terminate with the characters */ as shown
below:
/* my first program in C */
4. BASIC SYNTAX
You cannot have comments within comments and they do not occur within a
string or character literals.

Identifiers

A C identifier is a name used to identify a variable, function, or any other user defined item. An identifier starts with a letter A to Z, a to z, or an underscore ‘_’
followed by zero or more letters, underscores, and digits (0 to 9).
C does not allow punctuation characters such as @, $, and % within identifiers.
C is a case-sensitive programming language. Thus, Manpower and manpower
are two different identifiers in C. Here are some examples of acceptable
identifiers:

mohd              zara                 abc                 move_name             a_123 myname50    _temp            j                      a23b9                        retVal

Keywords

The following list shows the reserved words in C. These reserved words may not
be used as constants or variables or any other identifier names.

auto                            else                             long                           switch break                          enum                          register                      typedef case                             extern                         return                        union char                            float                            short                           unsigned const                           for                               signed                         void continue                    goto                            sizeof                          volatile default                        if                                  static                           while do                                int                               struct                          _Packed double