Introduction to Step-by-Step C/C++
Many people are really interested in learning and implementing
C/C++ programs on their favorite platforms like DOS/Windows or Linux. If you are the one looking for a step-by-step guide to get started, this tutorial is for you. Let me know your comments on my tiny attempt to serve the community.
Contents
I. About C
-
- What is C ?
- Development of C language
- C as a general purpose Language
- History of C
- Features of C
II. Programming Basics
- Components of a program
- Constants
- Data types
- Numeric Data Type
- Non-Numeric Data Type
- Integer Data Type
- Real Data Type
- Logical Data Type
- Enumerated Data Type
Introduction to Language & Expressions
What is C?
C is a compiler based programming language supports both high level and low level statements to interact directly with the hardware.
Development of C Language
The C programming language evolved from a succession of programming languages developed at Bell Laboratories in early 1970s. It was not until the late 1970s that this programming language began to gain widespread popularity and support. This was because until that time C compilers were not readily available for commercial use outside of Bell Laboratories.
The C language was the outcome of Dennis Ritchie’s work on a project in Bell Laboratories, to invent a suitable high level language for writing an Operating System which manages the input and output devices of a computer, allocates its storage and schedules the running of other programs.
UNIX operating system is written in the C language. Hence the Unix Operating system has C as its standard programming language. In fact over 90% of the operating system itself is written in the C language. So originally C language was designed and implemented on the Unix Operating System.
C as a general purpose Language
C is a high level, procedural/structured, and general purpose programming language and resembles few other high level languages such as Fortran, Pascal, and PL/1. However, we cannot call the C language as a “Purely High Level Language”.
C stands somewhere between the high-level languages meant for carrying on special activities and the low level languages such as assembly language of a machine because of some features like “System Independence”, “Limited Data Type”, “High Flexibility”, it is considered as a powerful language C has also become popular because of its portability across systems.
History of C
| Year | Language | Developed by | Remarks |
| 1960 | ALGOL | International Committee | Too general, Too abstract |
| 1963 | CPL | Cambridge University | Hard to learn, Difficult to implement |
| 1967 | BCPL | Martin Richards | Could deal with only specific problems |
| 1970 | B | Ken Thompson AT & T Bell Labs | Could deal with only specific problems |
| 1972 | C | Dennis Ritchie AT & T Bell Labs | Lost generality of BCPL and B restored |
| Early 80’s | C++ | Bjarne Stroustrup AT & T | Introduces OOPs to C. |
Features of C
- Simple, versatile, general purpose language
- Programs are fast and efficient
- Has got rich set of operators
- more general and has no restrictions
- can easily manipulates with bits, bytes and addresses
- Varieties of data types are available
- separate compilation of functions is possible and such functions can be called by any C program
- block-structured language
- Can be applied in System programming areas like operating systems, compilers & Interpreters, Assemblers etc.,
II. Programming Basics
Components of a program
1. Constants
2. Variables
3. Operators
4. Statements
So, before writing serious programming we must be clear with all the above components of programs. According to above example every program is a set of statements, and statement is an instruction to the computer, which is a collection of constants, variables, operators and statements.
Constants
A constant is a fixed value, which never altered during the execution of a program.
Constants can be divided into two major categories:
1. Primary Constants
2. Secondary Constants
Data Types
The kind of data that the used variables can hold in a programming language is known as the data type.
Basic data types are as follows:
1. Numeric Data Type
2. Non-Numeric Data Type
3. Integer Data Type
4. Real Data Type
5. Logical Data Type
6. Enumerated Data Type
1. Numeric Data Type: Totally deals with the numbers. These numbers can be of integer (int) data type or real (float) data type.
2. Non-Numeric Data Type : Totally deals with characters. Any character or group of characters enclosed within quotes will be considered as non-numeric or character data type.
3. Integer Data Type : Deals with integers or whole numbers. All arithmetic operations can be achieved through this data type and the results are again integers.
4. Real Data Type : deals with real numbers or the numeric data, which includes fractions. All arithmetic operations can be achieved through this data type and the results can be real data type.
5. Logical or Boolean Data Type : can hold only either of the two values TRUE or FALSE at a time. In computer, a 1 (one) is stored for TRUE and a 0 (zero) is stored for FALSE.
6. Enumerated Data Type : Includes the unstructured data grouped together to lead to a new type. This data type is not standard and us usually defined by user.
Ex.
Week_days = { “sun”, “mon”, “tue”, “wed”, “thu”, “fri”, “sat” };
Directions = {”North”, “East”, “West”, “South” };
The following table shows the standard data types with their properties.
| Keyword | Range: low | Range: high | Digits of precision | Bytes of memory | Format-ID |
| vhar | -128 | 127 | n/a | 1 | %c |
| int | -32, 768 | 32, 767 | N/a | 2 (on 16 bit processor)
| %d |
| long | -2,147, 483, 648 | 2, 147, 483, 647 | N/a | 4 | %ld |
| float | 3.4 x 10-38 | 3.4 x 1038 | 7 | 4 | %f |
| double | 1.7 x 10-308 | 1.7 x 10308 | 15 | 8 | %lf |
| long double | 3.4 x 10-4932 | 3.4 x 10-4932 | 19 | 10 | %Lf |
NOTE: The required ranges for signed and unsigned int are identical to those for signed and unsigned short. On compilers for 8 and 16 bit processors (including Intel x86 processors executing in 16 bit mode, such as under MS-DOS), an int is usually 16 bits and has exactly the same representation as a short. On compilers for 32 bit and larger processors (including Intel x86 processors executing in 32 bit mode, such as Win32 or Linux) an int is usually 32 bits long and has exactly the same representation as a long.
