Basic Syntax of C language

Well, now we have seen the basic structure of the C program that will help us in learning the syntax of the C language easily.

 

Tokens in C

C program includes various types of tokens like keyword, identifier and constants, etc.

Here is an example.

 

printf("Hello World! \n");

 

This example consists of 5 tokens. The following tokens are-

 

printf

(

   "Hello World! \n"

)

;

 

Semicolons

The semicolon is a statement terminator in a C program, which means each statement in the C language should end with a semicolon. The semicolon indicates the end of the statement. Your code will pop an error if you will not use this semicolon in the last of the statement.

 

Here is an example of the semicolons-

printf("Hello World! \n");

return 0;

 

Comments

If you want to label any line of code in the C program, you have to use comments because comments are the only one which is ignored by the compiler. The syntax to write a comment is as follows-

 

/* my first Hello World program in C */

 

A comment starts with "/*"  and ends with "*/"

 

Identifiers

The identifier in C is a name used to identify a variable function or any other item in the C program. Identifier starts with alphabets, underscores "_" and digits(0-9).

The C language does not allow any type of punctuation characters like"@, &, %, etc". This is why C is a very case sensitive programming language.

 

Here are some examples of identifiers-

 

abcd       rrtutors    abc   c_language  a_13

myname0   _temp   p     a29      programming

 

Keywords

The keywords are the reserved words that are used in the C language for initializing different variables or identifiers in C.

goto

do

enum

volatile

return

static

register

typedef

char

int

break

while

const

float

unsigned

_Packed

if

for

signed

long

else

auto

sizeof

switch

void

struct

case

short

default

extern

continue

union

double

 

 

 

 

 

Whitespace in C language

A line that contains the only whitespace is known as a blank line which is also ignored by the compiler.

Whitespace is usually used in C to define blanks, newlines and comments. Also, whitespace also divides the variable from keywords and explains to the compiler which one is a keyword or which one is a variable. Here is an example to explain my words.

 

int rollNo;

 

There must be a space between int and rollNo which helps the compiler to distinguish between them.

fruit = apples + oranges;   // To calculate the total fruit

We have used whitespace several times in the above program that helps the compiler to identify.

Whitespace is not necessary between "fruit" "=" "apples" "+" "oranges" in the above line. The compiler is quite intelligent to identify this line.