Note for Foundation of Computer Science - FCS By Jagan Reddy

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UNIT: I Overview of Computers and Programming, Data types, Operators and Expressions UNIT - I Overview of Computers and Programming - Electronic Computers Then and Now - Computer Hardware - Computer Software - Algorithm - Flowcharts - Software Development Method - Applying the Software Development Method. Data Types and Sizes - Constants -Types, Operators and Expressions: Variable Names Declarations - Arithmetic Operators - Relational and Logical Operators - Type Conversions Increment and Decrement Operators - Bitwise Operators - Assignment Operators and Expressions Conditional Expressions - Precedence and Order of Evaluation. 1.2 Introduction to Computers Computer is an advanced electronic device that takes raw data as input from the user and processes it under the control of set of instructions (called program), gives the result (output), and saves it for the future use. Today’s world is an information-rich world and it has become a necessity for everyone to know about computers. Purpose of this tutorial is to introduce you about computer and its fundamentals. Functionalities of a computer Any digital computer carries out five functions in gross terms: • • • • • Takes data as input. Stores the data/instructions in its memory and use them when required. Processes the data and converts it into useful information. Generates the output Controls all the above four steps. Definition Computer is an electronic data processing device which • • • accepts and stores data input, processes the data input, and generates the output in a required format. Advantages Following list demonstrates the advantages of computers in today's arena. Therisa T , CSE Department Page 1

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UNIT: I Overview of Computers and Programming, Data types, Operators and Expressions High Speed • • • • Computer is a very fast device. It is capable of performing calculation of very large amount of data. The computer has units of speed in microsecond, nanosecond, and even the picosecond. It can perform millions of calculations in a few seconds as compared to man who will spend many months for doing the same task. Accuracy • • • In addition to being very fast, computers are very accurate. The calculations are 100% error free. Computers perform all jobs with 100% accuracy provided that correct input has been given. Storage Capability • • • • Memory is a very important characteristic of computers. A computer has much more storage capacity than human beings. It can store large amount of data. It can store any type of data such as images, videos, text, audio and many others. Diligence • • • Unlike human beings, a computer is free from monotony, tiredness and lack of concentration. It can work continuously without any error and boredom. It can do repeated work with same speed and accuracy. Versatility • • • • A computer is a very versatile machine. A computer is very flexible in performing the jobs to be done. This machine can be used to solve the problems related to various fields. At one instance, it may be solving a complex scientific problem and the very next moment it may be playing a card game. Reliability • • • A computer is a reliable machine. Modern electronic components have long lives. Computers are designed to make maintenance easy. Automation • Computer is an automatic machine. Therisa T , CSE Department Page 2

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UNIT: I Overview of Computers and Programming, Data types, Operators and Expressions • • Automation means ability to perform the given task automatically. Once a program is given to computer i.e., stored in computer memory, the program and instruction can control the program execution without human interaction. Reduction in Paper Work • • The use of computers for data processing in an organization leads to reduction in paper work and results in speeding up a process. As data in electronic files can be retrieved as and when required, the problem of maintenance of large number of paper files gets reduced. Reduction in Cost • Though the initial investment for installing a computer is high but it substantially reduces the cost of each of its transaction. Disadvantages Following list demonstrates the disadvantages of computers in today's arena No I.Q • • • A computer is a machine that has no intelligence to perform any task. Each instruction has to be given to computer. A computer cannot take any decision on its own. Dependency • It functions as per a user’s instruction, so it is fully dependent on human being Environment • The operating environment of computer should be dust free and suitable. No Feeling • • Computers have no feelings or emotions. It cannot make judgement based on feeling, taste, experience, and knowledge unlike a human being. Computer – Applications Following list demonstrates various applications of computers in today's arena. Banking Today banking is almost totally dependent on computer. Therisa T , CSE Department Page 3

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UNIT: I Overview of Computers and Programming, Data types, Operators and Expressions Banks provide following facilities: • • Banks provide online accounting facility, which includes current balances, deposits, overdrafts, interest charges, shares, and trustee records. ATM machines are making it even easier for customers to deal with banks. Insurance Insurance companies are keeping all records up-to-date with the help of computers. The insurance companies, finance houses and stock broking firms are widely using computers for their concerns. Insurance companies are maintaining a database of all clients with information showing • • • • • • • procedure to continue with policies starting date of the policies next due installment of a policy maturity date interests due survival benefits bonus Education The computer has provided a lot of facilities in the education system. • • • • • The computer provides a tool in the education system known as CBE (Computer Based Education). CBE involves control, delivery, and evaluation of learning. The computer education is rapidly increasing the graph of number of computer students. There are number of methods in which educational institutions can use computer to educate the students. It is used to prepare a database about performance of a student and analysis is carried out on this basis. Marketing In marketing, uses of computer are following: • • Advertising - With computers, advertising professionals create art and graphics, write and revise copy, and print and disseminate ads with the goal of selling more products. At Home Shopping - Home shopping has been made possible through use of computerised catalogues that provide access to product information and permit direct entry of orders to be filled by the customers. Health Care Therisa T , CSE Department Page 4