practising C, C++ and JAVA programming with examples

Explain system designing tools.

q)Explain system designing tools.
ans:-

Systems Design: In this phase we start design of proposed new system.It describes desired features and operations in detail, including screen layouts, business rules, process diagrams, pseudo code and other documentation. We can use two designing methods namely logical (what is required for IS) and physical (how to achieve requirements). At first we design logical and then it is converted into physical design. A prototype should be developed during the logical design phase if possible. The detailed design phase modifies the logical design and produces a final detailed design, which includes technology choices, specifies a system architecture, meets all system goals for performance, and still has all of the application functionality and behavior specified in the logical design.

This design can carry following activities:

Defining precisely the required system output
Determining the data requirement for producing the output
Determining the medium and format of files and databases
Devising processing methods and use of software to produce output

We can use several tools while designing. They are: Algorithm, Flowchart, Pseudo code, etc. Let’s see in detail about some of these all designing tools.

I) Algorithm:

An algorithm is an effective method or a tool for solving a problem using a finite sequence of well organized instructions. Algorithms are used for calculation, data processing, and many other fields.

Each algorithm is a list of well-defined instructions for completing a task. Starting from an initial state, the instructions describe a computation that proceeds through a well-defined series of successive states, eventually terminating in a final ending state. For example,

-->start

-->read a no. x

-->read a no. y

→ let sum=x+y

-->display sum

-->stop

II) Flowchart:- It is a common type of diagram or picture, that represents an algorithm or process, showing the steps as boxes of various kinds, and their order by connecting these with arrows. Or simply we can say a graphical representation of algorithm. Flowcharts are used in analyzing, designing, documenting or managing a process or program in various fields. Some symbols used in flowcharts are Oval, parallelogram, rectangle, flowline, annotation etc. different symbols have different meanings. For example,

Pseudo Code:

Pseudo-Code is simply a numbered list of instructions to perform some task. Here Pseudo means fake. So it is a fake code which we use to convert algorithms. In this we use many English words or verbs like START/BEGIN, DO, WHILE, HALT,STOP,INITIALIZE etc, Any case can be used. Writing Pseudocode is just like reading a story. So it’s easy to write and understand. For example,

BEGIN

GET GRADE

IF student's grade is greater than or equal to 80

Print "passed in distinction"

ELSE

Print "other division"

HALT

Who is system analyst? Explain his/her skills to be with.

q)Who is system analyst? Explain his/her skills to be with.
ans:-
system analyst:-

The persons who perform above task/system analysis,design and implementation activity is know as system analyst. Somewhere we say or call by names like business engineer, business analyst etc. The work of system analyst who designs an information system is just same as an architect of a house. They work as facilitators of the development of information systems and computer applications.

skill to be with:-

following are the skills of system analyst.

1) Analytical skill:- Analytical skill is the ability to visualize, articulate (express), solve complex problems and concepts, and make decisions that make sense based on available information. Such skills include demonstration of the ability to apply logical thinking to gathering and analyzing information, designing and testing solutions to problems, and formulating plans.

2) Technical skill: Many aspects of the job of system analysts are technically oriented. In order to develop computer based IS (information systems), system analyst must understand information technologies, their potentials and their limitations. A system analyst needs technical skills not only to perform tasks assigned to him but also to communicate with other people with whom s/he works in system development. The technical knowledge of SA must be updated from time to time. S/he should be familiar with technologies such as:

>Micro/mini/mainframe computers, workstations

>Programming language

>Operating systems, database and file management systems, data communications standard system development tools and environments, decision support systems.

3)Managerial skill:-Management in all business is the act of getting people together to accomplish desired goals and objectives. This skill comprises planning, organizing, staffing, leading or directing, and controlling an organization (a group of one or more people or entities) or effort for the purpose of accomplishing a goal.

4)Interpersonal skill:-

Interpersonal skills are the life skills we use everyday to communicate and interact with other people, both individually and in groups. It includes

verbal communication
non-verbal communication
listening skills
problem solving
decision making
assertiveness (Communicating our values, ideas, beliefs, opinions, needs and wants freely.

Who is system analyst? Explain his/her roles.

q)Who is system analyst? Explain his/her roles.

ans:-
System analyst:-

His/her roles:-

Defining Requirement: It's very difficult duty of analyst to understand user's problems as well as requirements. some techniques like interview, questioning, surveying, data collection etc have to be used. The basic step for any system analyst is to understand the requirements of the users.

Prioritizing Requirements: Number of users use the system in the organization. Each one has a different requirement and retrieves different information and in different time. For this the analyst must have good interpersonal skill, convincing power and knowledge about the requirements and setting them in proper order of all users.

Gathering Facts, data and opinions of Users: After determining the necessary needs and collecting useful information the analyst starts the development of the system with active cooperation from the users of the system. Time to time, the users update the analyst with the necessary information for developing the system. The analyst while developing the system continuously consults the users and acquires their views and opinions.

Evaluation and Analysis: Analyst analyses the working of the current information system in the organization and finds out extent to which they meet user's needs. on the basis of facts,opinions, analyst finds best characteristic of new system which will meet user's stated needs.

Solving Problems: Analyst is actually problem solver. An analyst must study the problem in depth and suggest alternate solutions to management. Problem solving approach usually has steps: identify the problem, analyse and understand the problem, identify alternate solutions and select best solution.

Drawing up Specifications: The analyst must draw certain specifications which will be useful for the manager. The key duty of system analysis is to obtain the functional specification of the system to be designed. The specification must be non-technical so that users and managers understand it. The specification must be precise and detailed for implementers.

Designing system:- Once accepted the specification, the analyst starts to design system. The design must be understandable to the system implementer. The design must be modular to accommodate changes easily. There must be a good knowledge of latest tools and how to use them in system with testing idea.

Q2)Explain different phases used in system development

Explain different phases used in system development
ans:-
Th steps of SDLC are shown below.

Let's know about them in brief.

1)Problem definition:-The first step is problem definition(study). The intent is to identify the problem, determine its cause, and outline a strategy for solving it. It defines what ,when who and how project will be carried out.

2) System analysis:-

Once the problems identified, it is time to analyze the type of software that could answer the problems encountered. System analysis (may be by system analyst) will take a look at possible software. The goal of a system analysis is to know the properties and functions of software that would answer the concerns solicited from intended users.

Step 3.

.step 4 System Development:-

System development (Coding):

After designing the new system, the whole system is required to be converted into computer understanding language. Coding the new system into computer programming language does this. It is an important stage where the defined procedure are transformed into control specifications by the help of a computer language.

step 5. Testing:-

Before actually implementing the new system into operations, a test run of the system is done removing all the bugs, if any. It is an important phase of a successful system. After codifying the whole programs of the system, a test plan should be developed and run on a given set of test data. The output of the test run should match the expected results.

step 6 Implementation

After having the user acceptance of the new system developed, the implementation phase begins. Implementation is the stage of a project during which theory is turned into practice. During this phase, all the programs of the system are loaded onto the user's computer. After loading the system, training of the users starts. Main topics of such type of training are:

How to execute the package
How to enter the data
How to process the data (processing details)
How to take out the reports

step 7 System Evaluation:-
Management should conduct post-implementation reviews at the end of a project to validate the completion of project objectives and assess project management activities. Management should interview all personnel actively involved in the operational use of a product and document and address any identified problems.

8. System Maintenance:-

Maintenance is necessary to eliminate errors in the system during its working life and to tune the system to any variations in its working environment. It has been seen that there are always some errors found in the system that must be noted and corrected. It also means the review of the system from time to time. The review of the system is done for:

knowing the full capabilities of the system
knowing the required changes or the additional requirements
studying the performance

What is feasibility study? Explain its types.

Q)What is feasibility study? Explain its types.

Ans:
Feasibility study:-
It is the measure and the study of how beneficial the development of the system would be to the organization. This is known as feasibility study. The aim of the feasibility study is to understand the problem and to determine whether it is worth proceeding.
It has following types.

1.Technical feasibility: - This is concerned with availability of hardware and software required for the development of system.The issues with can be like:

1.1) Is the proposed technology proven and practical?

1.2)the next question is: does the firm possess the necessary technology it needs. Here we have to ensure that the required technology is practical and available. Now, does it have required hardware and software?

1.3)The Last issue is related to availability of technical expertise. In this case, software and hardware are available but it may be difficult to find skilled manpower.

2.Operational feasibility:- It is all about problems that may arise during operations. There are two aspects related with this issue:

2.1) what is the probability that the solution developed may not be put to use or may not work?

2.1) what is the inclination of management and end users towards solutions?

Besides these all some more issues;

a) Information: saying to provide adequate, timely, accurate and useful information to all categories of users.

b) Response time, it says about response about output in very fast time to users.

c) Accuracy: A software system must operate accurately. It means, it should provide value to its users. It says degree of software performance.

d) Services:- The system should be able to provide reliable services.

e)Security:- there should be adequate security to information and data from frauds.

f) Efficiency: The system needs to be able to provide desirable services to users.

3) Economic feasibility: - It is the measure of cost effectiveness of the project. The economic feasibility is nothing but judging whether the possible benefit of solving the problem is worthwhile or not. Under "cost benefit analysis", there are mainly two types of costs namely, cost of human resources and cost of training.

The first one says about salaries of system analysts, software engineers, programmers, data entry operators etc. whereas 2nd one says about training to be given to new staffs about how to operate a newly arrived system.

4) Legal feasibility: - It is the study about issues arising out the need to the development of the system. The possible consideration might include copyright law, labor law, antitrust legislation, foreign trade etc.

Apart from these all we have some more types:

behaviour feasibility, schedule feasibility study etc.

NEB41:Explain datatypes used in “C”.

Q41)Explain datatypes used in “C”.

ans:-
Data type:-
When we write program we use different variable. Before we use them in our program we declare them with their data format to be used in memory. This format is called 'data type'.
Following are the types.There are two types of data types.

a) Basic data type (Primary data type)

b) Derived data type(Secondary data type) mostly called "Qualifier"

Let's have look in detail about primary data types.

a) Basic data type:- Under this category we have four types. They are int,float,char and double.Let's know about them.

a.1) int:-

It's a basic data type; we can use only integer type of value by declaring variable with this. e.g

int sum;

This declaration declares sum as integer type of variable. We can use or input only integer type of value and under some range. We can not use other values like fractional or exponential. And if we used then, the computer truncates the fractional part. eg. int sum=3.4;

Here, we used int data type but assigned fractional value (3.4); So computer stores only 3 instead of 3.4. It occupies 2 bytes in memory and working range is -32768 to +32767.

a.2) float:-

Suppose, we want to use fractional numbers; then we use float data type. This type supports numbers with decimal digits(after dot) for a variable. Unlike integer (int ), it does not truncate the fractional part and whole part is stored in memory.

float pi=4.67;

float a=6;

We have taken simple examples. In first. the computer stores 4.67 in memory. Where as in second we can see that number is integer but it has been declared as float, in this case computer automatically converts the integer into float by putting dot and zeros. i.e computer takes 6.00. In memory computer occupies 4 bytes for this and can store up to or in range 3.4e-38 to 3.4e+38;good range it has to work with.

a.3) Char:-

Char stands for a single character or sequence of many characters. We use this data type if we want to use one character or a set (called string) to be inputted. To be clear, let's have an example,

syntax goes like,

data type variable/s;

char a,b;

here, a and b are character type of variables and can store one character. If we want to store one character as a constant then we can assign like,

char a='n';

here, a is character type of variable and is storing 'n';

But if we want to store more than one character or input then we can use,

char a[10];

here, we can enter a string having maximum ten characters;we can also enter just one character. This concept is called arrayed characters. In the case of constant,we use

char a[10]="text";

String "text" is stored in variable 'a' and it can store maximum 10 characters.

a.4) Double:-

This data type is used for exponential values and for more accuracy of digits.It's working range is more than others. so if we want to use long numbers of any type and high accuracy then...? for example,

data type variable;

double ab;

'ab' is a variable of double type. It can store exponential values (3x104). It ca n be written as 3e+4 or 3E+4. If power is in negative form then it can be in 3e-4 or 3E-4. It has one advantage over others that it can be used in place of others easily.

neb40:Explain about operator and its types.

ans:
operator:- It is a symbol or a character used in programming. It is used to carry out some operation.
for example: +,-,= etc
It is of following types.
1)Arithmetic operator: It is used to do arithmetic calculations/operation.
It has following types.

+ -----------> used for addition.example is a+b. It means we are performing addition with the help of operand a and b
- ------------>It is used for subtraction.Example is a-b. It means we are performing subtraction with the help of operand a and b
* -------------------->used for multiplication.example is a*b. It means we are performing multiplication with the help of operand a and b
/---------------->used for division.example is a/b. It means we are performing division with the help of operand a and b

%---------------->used for remainder division.example is a%b. It means we are performing division with the help of operand a and b.It gives us remainder after division.

2)relational operator:

This operator is used to perform comparisons between variables.It supports us to take decision logically. example,x>y ,x>=y etc

Relational operator has following types.

>------> It is used to show greater than. like x>y

>=----->It is used to show greater than or equals to.like x>=y

<-------->It is used to show a variable is smaller than another.like x<y

<=-------> It is used to show smaller than or equals to with another variable.Like x<=y

!=----------> I simply says , two variables are not equal in value.like x!=y

==---------->It says two variables have same value.It is used to test values of two variables.

3)Logical operator:-

This operator is quite helpful when we want to combine multiple conditions and take decision.It returns values in the form of 0 o 1.It works logically.

Its types are:

3.a)and (&&)-----------> It is called 'and'operator.It is used to combine multiple conditions.It gives us true output if all of them are true otherwise we get false output.

example:if(a>b && a>c)

{

display a

}

we can see here that to be greatest,value of 'a' must be greater than b and c. So we use here '&&'

3.b)or(||):- It is called 'or'operator.It is used to combine multiple conditions.It gives us true output if anyone of them is true or all are true otherwise we get false output.

example:if(a==90 || b==90 || c==90)

{

display right angle triangle

}

we can see here that to be right angled triangle,either 'a'or 'b'or 'c' a must be 90 . So we use here '||'.

3.c) !(not )operator:-

It is used to reverse the result.
example
int a=5;
if(!(a==5))
{
printf("it is\n");
}
else
{
printf("it is not\n");
}
here ,the value is 5 but we get output "it is not".It is called reversing the output.

4) Assignment operator:
an operator ,symbolized by '=' character,is called assignment operator.It assigns value to variable.
example:
int a=6;
It means, we are assignming value 6 to variable a.

5)Unary operator:- this operator works on one operand only.It has two types.
I) increment operator:- It increases the value of given variable by one.For example: ++y or y++
It can be classified into pre-increment and post increment.
pre-increment:- It is written as ++x.It means first increase the value and then use that.
post-increment: It is written as x++.It means, first use that and then increase its value by one.

II)decrement operator:- It decreases the value of given variable by one.For example: --y or y--
It can be classified into pre-decrement and post decrement.
pre-decrement:- It is written as --x.It means first decrease the value and then use that.
post-decrement: It is written as x--.It means, first use that and then decrease its value by one.

Besides these all, we have some other operators .like bitwise,