C - Basic Syntax

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

                                                 TOKENS IN C

A programming token is the basic component of source code . C tokens are the basic buildings blocks in C language which are constructed together to write a C program.For example, the following C statement consists of SIX  tokens

C tokens are of six types. They are,

1. Keywords               (eg: int, while),
2. Identifiers              (eg: main, total),
3. Constants              (eg: 10, 20),
4. Strings                    (eg: “total”, “hello”),
5. Special symbols  (eg: (), {}),
6. Operators              (eg: +, /,-,*)

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 statement f("Hello, World! \n");

return 0;

Comments

Comments are  just 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 */

You cannot have comments within comments and they do not occur within a string or character 

2. IDENTIFIERS IN C LANGUAGE:

• Each program elements in a C program are given a name called identifiers.

• Names given to identify Variables, functions and arrays are examples for identifiers. eg. x is a name given to integer variable in above program.

 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, Manpowerand 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.

• Keywords are pre-defined words in a C compiler.
• Each keyword is meant to perform a specific function in a C program.
• Since keywords are referred names for compiler, they can’t be used as variable name.

C language supports 32 keywords which are given below. Click on each keywords below for detail description and example programs.

auto	double
int	struct
const	float
short	unsigned
break	else
long	switch
continue	for
signed	void

case	enum
register	typedef
default	goto
sizeof	volatile
char	extern
return	union
do	if
static	while

Whitespace in C

A line containing only whitespace, possibly with a comment, is known as a blank line, and a C compiler totally ignores it.

Whitespace is the term used in C to describe blanks, tabs, newline characters and comments. Whitespace separates one part of a statement from another and enables the compiler to identify where one element in a statement, such as int, ends and the next element begins. Therefore, in the following statement −

int age;

fruit = apples + oranges;   // get the total fruit

no whitespace characters are necessary between fruit and =, or between = and apples, although.