Basic Information related to C language or Programming language

Hello, Viewer's in the previous post we learn about the translator (Compiler, Interpreter). Now in this post, we learn about the C programming language. So let's start
History of C language

C language was developed by the "Dennis Ritchie" in 1972 at BT & T laboratories. (also check the images for more history of C )

It is a combination of high-level programming language.
It is used in almost all software.
It is fast, reliable and highly portable and can run under a various operating system.

Application of C

C language finds in business, education, scientific etc field. It provides various type operation and statements to solve computationally problem.
C is used in system software such as operating system, compiler etc and application software such as verification software, test code etc.

Some Important terms
There are many important terms/topic in the programming world. we study all terms one by one.

Identifiers
Identifier is a fundamental building block of the program and it is a combination of permissible character.
Rules for writing an Identifier

Only alphabetic letters, digits and underscore are permitted in an identifier.
An Identifier name can't start with a digit.

Keywords
There is some identifier in C which have predefined meaning these identifiers are called keywords.
Examples: int, char, float, sizeof, void etc.

Tokens
Tokens is a group of characters which represent keywords, operators, and identifiers.

Examples:

Keywords
Identifiers ( declare by the program )
Operator ( +, -, <, >, =, etc. )
Numeric ( 24, 24.35, 0.08 etc. )
Characters

Constant

Constant are the fixed data value that do not change their values during the execution of a program. these are also called "Literals".

Variables

Variable is a name of the memory location where a program saved. we can change the value of a variable during the execution of a program.

Rules for Naming a Variable

The first character of a variable should always be the alphabet.
Special character ( except- Underscore ) can't be part of a variable name.
The Variable name can have a combination of Lowercase & Uppercase.
The variable should not be a keyword.

Datatypes in C

There are various datatypes in C are follows:-

Primitive Datatype
Derived Datatype
User Defined Datatype

1. Primitive Datatype

It includes

Characters or char ( a,b,v etc )
Integer or int ( 21, 20, 98 )
Floating ( 20.2, 23.26,0.08 )
Fixed Point Number

2. Derived Datatype

C also supports three types of derived data

Array
Function
Pointer

3. User Defined datatype

C support three type of user-defined datatype

Structure
Union
Enumerated

Integer

Any Numbers which have no points.

Example: 50, 0, -44

Character

In which include single codes ( ' ' ) and only one symbol.

Example: 'a', 'b', 'l' etc.

Floating

Any Numbers which have points.

Example: 20.0, 52.3, 89.9 etc.

Array

An array is a linear collection of similar elements. An array is also known as "Subscript Value".
An array is a group of a variable.
Array indices start at Zero in C and go to one less than the size of array.

Declaration of Array:

variable_name[num_elements]

Example:

int A[100];

It creates an array A with 100 integer elements.
The size of array A can't be changed.
The number between brackets must be a constant.

Initialization of an Array:

int A[5] = {0,1,2,3,4}; // Array can be initialize during declaration

Pointer

A pointer is a variable that contains the address of another variable.
Pointer always consumes 2 bytes in memory. ( for a 16-bit compiler )

Syntax

data_type*variable_name

Example

int *p;

char*p;

where * is used to denote that "p" is pointer variable and not a normal variable.

The value of a null pointer is zero.
"&" symbol is used 2 get the address of a variable.
"*" symbol is used 2 get the value of the variable.

Thanks 4 reading our blog! hope you like it. In the next post we'll discuss more basic fundamentals related to programming world.