Page 171 - DCAP404 _Object Oriented Programming

Object-oriented Programming

Notes You should get the following output.
Stock Details-stock1-type
code 101
Items 10

Price per item `125
Stock value
1250
Stock Details-stock2-type

code 10 1
Total Value `1250

Self Assessment

Fill in the blanks:
14. Typecasting is making a variable of one type, such as an int, act like another type, a
………………….. , for one single operation.
15. One special case of implicit type conversion is type promotion, where the compiler
automatically expands the …………………….. representation of objects of integer or
floating-point types.

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Caselet Learn to Think Like the Computer Thinks

o learn to program a computer you need to learn to think like the computer thinks,
advises Jim Messinger in Starting Out With Programming Logic & Design, and
Tintroduces readers first to friendly definitions of terms such as variable, constant,
pseudocode, counter and so on.
Thus, you’d learn that ‘flag’ is related to flagging of data. It is similar to flagging in car
races where the flag tells you to take a specific action, explains Messinger.

“In a computer, the flag is on when it is 1 and off when it is zero. In car races, there are a
variety of flags: yellow, white, checkered, and so on. Each of these could be represented in
a computer by an appropriately named variable and could be set to 0 or 1 to indicate to the
computer program the state of the car race.”
Again, when explaining modules as collections of related tasks, the author uses the
automotive example: “Think of a car as a program. Its modules could be the engine,
transmission, and body.” Remember that modules can become complex, which is when
you need sub-modules, such as “fuel system, ignition system, and exhaust system” for the
engine.
With Lord Falkland’s quote - “When it not necessary to make a decision, it is necessary not
to make a decision” - begins a chapter on `selection logic’. If you’re familiar with flowchart
symbols, you may know selection as what you do when a `diamond’ is encountered.
Contd...

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