[ITP - Lecture 02] Steps to Create Program & Approaches of Programming

Steps & Approaches of Programming Intro to Programming
MUHAMMAD HAMMAD WASEEM 1
Creating and Editing a C Program:
To write the first C program, open the edit window of the Turbo C++/Borland C++ IDE (Integrated
Development Environment). This can be done by selecting File→New option from the Menu bar. A
window appears on the screen. This window has a white working area, and a cursor inside Window
represents the starting point to write a program.
Saving a C program:
After writing the C program, we should save it on the disk. This can be done by selecting
File→Save command from the menu bar or press Ctrl+K S keys together, there is a text box with Caption
Save File As type the Name of file. The editor assigns a default name NONAME00.cpp to the file, to save
a file to the specific folder/location with the File name, one has to specify the absolute path.
Compiling a C program:
The computer does not understand source program because instructions in the program are
meaningless to the microprocessor as it understands only the machine language. A program that is to
be executed must be in the form of machine language. C compiler translates the source program into an
object program with .obj extension. To invoke compiler, select Project→Compile from the menu bar or
press Alt+F9. If there is no error in the source program, the program will be translated to the object
program successfully. Otherwise, the compiler will report errors in the program.
Linking a C program:
While writing a C program, the programmer may refer to many files to accomplish various tasks
such as input/output etc. In case of c language a lot of functionality is available in the form of library
files. Such files are needed to be linked with the object file, produce by the complier, before execution
of the program.
Linking in the process in which the object file produce by the compiler is linked to many other
library files by the linker. The linker is a program that combines the object program with additional object
files may be needed for the program to execute and save the final machine language program as n
executable file on the disk. The linker combines different library files to the object file and produces an
executable file with .exe extension.
Executing a C program:
After successfully compiling and linking the program, we are now ready to execute it. For
execution the program must be loaded in memory. This is done by the loader. Loader is a program that
places executable file in memory. This is done by selecting Debug→Run from the menu bar or pressing
Ctrl+F9 key.

Steps & Approaches of Programming Intro to Programming
MUHAMMAD HAMMAD WASEEM 2
Programming Approaches:
Non-Structured Programming
Non-structured programming, which frequently working with GO TO branch points to transfer
from one part of the program to another part. Using GO TO codes, one could transfer backward, forward,
or anywhere else within the program. The problem is that the connections between parts of the program
by using GO TO commands can become quite messy.
This type of programming is difficult to understand and debug. Non-structured programming of
this nature is now viewed as an ineffective programming strategy.
To develop good software, developers have to carefully think out and design the programs. In
the earliest days of computing, programmers wrote software according to their own whims (desires),
with the result that programs were often confusing and difficult to work with. Software today is expected
to follow recognized design principles. The prevailing design standards are structured programming and
structured design.
Structured Programming
Structured programming was invented to address the shortcomings of nonstructural
programming. Structured programming makes use of the control structures (sequence, selection and
repetition). Structured programming does not use GO TO commands. The sequence principle implies
that program instructions should be executed in the order in which they appear. The selection principle
implies that instructions may be executed selectively using IF-THEN and/or IF-THEN-ELSE statements.
These statements work in the following way. IF a condition is met or is true, THEN a specific set of
instructions will be executed. If the condition is false, then another set of instructions will be executed.
For example, ______________.
Alternatively when there are many options, one can employ the CASE statement.
The iteration principle indicates that one part of the program can be repeated or iterated a
limited number of times. In most computer languages, the iteration may be activated by using REPEAT -
--UNTIL or using the WHILE loop and the FOR loop.
Modular Programming
The Modular Approach to programming involves breaking a program down into subcomponents
called modules. Each module is composed of an independent or self-contained set of instructions.
Modules are also referred to as routines, subroutines, or subprograms or procedures. Each module is
designed to perform a specific task in the overall program, such as to calculate the gross pay of an
employee in a payroll program.
The advantage of modular programming is the ability to write & test each module independently
and in some cases reuse modules in other programs. A program can consists of multiple modules. In
addition, there is a main module in the program that executes the other modules.

[ITP - Lecture 02] Steps to Create Program & Approaches of Programming

Recommended

More Related Content

What's hot (20)

Similar to [ITP - Lecture 02] Steps to Create Program & Approaches of Programming (20)

More from Muhammad Hammad Waseem (20)

Recently uploaded (20)

[ITP - Lecture 02] Steps to Create Program & Approaches of Programming