Connector A small, labeled, circular flow
chart shape used to indicate a jump in the process
flow.
Data A parallelogram that indicates
data input or output (I/O) for a process.
Program Development Steps:
1.
Statement of
Problem
a)
Working with existing system and using proper
questionnaire, the problem should be explained clearly.
b) W hat inputs are available, what outputs are required and
what is needed for creating workable
solution, should be understood clearly.
2.
Analysis
a)
The method of solutions to solve the problem can be
identified.
b) We
also judge that which method gives best results among different methods of
solution.
3. Design
a) Algorithms
and flow charts will be prepared.
b) Focus on
data, architecture, user interfaces and program components.
4. Implementation
The algorithms and
flow charts developed in the previous steps are converted into actual programs
in the high level languages like C.
a.
Compilation
The process of
translating the program into machine code is called as Compilation. Syntactic
errors are found quickly at the time of compiling the program. These errors
occur due to the usage of wrong syntaxes for the statements. Eg: x=a*y+b
There is a syntax error in this statement, since, each and
every statement in C language ends with a semicolon (;).
b.
Execution
The next step is Program execution. In this phase, we may encounter two
types of errors. Runtime Errors: these errors occur during the execution of the
program and terminate the program abnormally.
Logical Errors: these errors occur due to incorrect usage of
the instructions in the program. These errors are neither detected during
compilation or execution nor cause any stoppage to the program execution but
produces incorrect output.
General Structure of a C program:
/*
Documentation section */
/*
Link section */
/*
Definition section */
/* Documentation section */
/* Link section */
/* Definition section */
/* Global declaration section */
main()
{
Declaration part
Executable part (statements)
}
/* Sub-program section */
The documentation section is used for displaying any information about the program like the
purpose of the program, name of the author, date and time written etc, and this section should
be enclosed within comment lines. The statements in the documentation section are ignored by
the compiler.
The link section consists of the inclusion of header files.
The definition section consists of macro definitions, defining constants etc,.
Anything declared in the global declaration section is accessible throughout the program, i.e.
accessible to all the functions in the program.
main() function is mandatory for any program and it includes two parts, the declaration part and
the executable part.
The last section, i.e. sub-program section is optional and used when we require including user
defined functions in the program.