1.5 Itse1359-1030-variables and identifiers  (Page 5/7)

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It also causes a reference to the new object to be stored in the variable named b , replacing the reference to a different object that was previously stored there.

You will be learning a lot more about objects as well as the code visualizer tool in future modules.

Type considerations

In most modern programming systems, values having fractional parts, such as 3.14159 are commonly referred to as floating point types. (This terminology comes from the fact that the decimal point can float back and forthfrom left to right.)

Similarly, whole number values are commonly referred to as integer types. (These are values with no decimal parts, such as, "I have 3 whole apples.")

Each type has advantages and disadvantages relative to the other when performing computations.

The range of values

For example, in some systems, the total range of values for a particular integer type is restricted to the set of whole numbers between -32768 and +32767. Anythingoutside that range cannot be handled as a whole number of that integer type.

Although the range of an integer type will be different on different systems, it will almost always be less than the range of a floating point type on thesame system.

Speed

On some systems integer arithmetic is performed much faster than floating point arithmetic. On those systems, if speed is important, usingintegers may be more attractive than using floating point types.

Floating point provides greater range

On most systems, the floating point type provides a much greater range in terms of the values that can be maintained and used for arithmetic. For example,a particular system might be capable of representing the following two values as well as millions of values in between:

• 0.000000000033333
• 333330000000000.0

Sometimes range is important, and sometimes not

Sometimes range is important, and sometimes it isn't. However, as I mentioned above, in some systems this greater range is obtained at some sacrifice inarithmetic speed relative to integer types.

Approximate results

Also, as I will explain in the Review module that goes with this module, floating pointarithmetic often produces approximate results instead of exact results.

While approximate results might be OK for some scientific calculations, they might not be OK for other calculations such as financial calculations for example.

Automatic type handling in Python

In strongly-typed languages such as Java, it is the responsibility of the programmer to make certain that types are handled correctly. For example, itis often not possible to store a floating point value into a variable previously declared to be for the storage of integer values. There is a very strongpossibility that it simply won't fit.

Python takes care of routine type issues automatically

Consider the interactive code fragment shown in Figure 5 . The variables x and y are originally created to store integers and are populated with thevalues 5 and 6 respectively. The variables are added and the correct sum is displayed as output from the interpreter.

anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
how did you get the value of 2000N.What calculations are needed to arrive at it
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