When Charles Babbage made the computer, he had yet to
figure out about how to give the machine instructions. The first ever
programming language was written by Ada Lovelace in the year of 1883. The code
was for computing Bernoulli’s number and hence that was the first time the
computing power of the machine was seen in action.

In the 1949, Assembly language, a type of low-level
language, came into play.it only consists of symbols/instructions that only
computer can understand and interpret. It is still used till this day in the
aviation systems and medical equipment.

The first complied computer program is Autocode and
was developed by Alick Glennie in the year 1952.

In the year of 1957, FORTRAN was developed for numeric
and scientific calculations. The program developed by John Backus and IBM. This
was the first optimizing compiler. It was used for scientific purposes like for
computing numerical weather predictions, fluid dynamics, geophysics, crystallography,
computational chemistry etc. It was in the software for NASA probes voyager-1
and voyager-2. With years it came with different and better versions.

Algorithmic language, also known as ALGOL, was the
first programming language to implement nested function and had a simpler syntax
than that of the FORTRAN. It was built in the year 1958. It is family of
interactive computer programming languages. It used the code block like, ‘begin’
to start and ’end’ to end the code. It was designed to avoid some of the
problems in FORTRAN. Iwas designed by Baue, Bottenbruch, Rutishauser, Samelson,
Backus, Katz, Perlis, Wegstein,Naur, Vanquois, van Wijingarden, Wooder ,Green, McCarthy.

COBOL, also known as Common Business-Oriented
Language. As the name suggests the code was specifically useful in business. In
19777, 80% of the world’s business was handled by COBOL. It is widely used for
applications deployed on mainframe computer. It was developed by Howard
Bromberg, Norman Discount, Vernon Reeves, Jean E. Sammet, William Selden,
Gertrude Tierney along with the indirect influence from Grace Hopper.

By 1964, we had BASIC. It stands for Beginners
All-Purpose Symbolic Instruction Code. In the year 1991, Microsoft came out
with Visual Basic, an updated version of the previous one. The first
microcomputer version was developed by Bill Gates, Paul Allen and Monte
Davidoff for their company Microsoft, right after they formed it.

And one of the most commonly used computer programming,
and the mother of almost all higher-level languages, C, came into existence in
the year of 1972. It is a procedural language. All the codes that were previously
written in assembly language was replaced by C. Those include operating systems
like Kernel and others. It can be used by implementing an operating system, embedded
system and also website using CGI- Common Gateway Interface.

  ENCAPSULATION IN JAVA WITH EXAMPLES 

BY- RAJESHWARI KUWAR

  The process of binding data and corresponding methods (behavior) together into a single unit is called encapsulation in Java.

In other words, encapsulation is a programming technique that binds the class members (variables and methods) together and prevents them from being accessed by other classes.

Thereby, we can keep variables and methods safes from outside interference and misuse.

Every Java class is an example of encapsulation because we write everything within the class only that binds variables and methods together and hides their complexity from other classes.

Another example of encapsulation is a capsule. Basically, the capsule encapsulates several combinations of medicine.

If combinations of medicine are variables and methods then the capsule will act as a class and the whole process is called Encapsulation as shown in the below figure.

In the encapsulation technique, we declare fields as private in the class to prevent other classes from accessing them directly. The required encapsulated data can be accessed by using the public Java getter and setter method.

 If the field is declared private in the class, then it cannot be accessed by anyone from outside the class and hides the field within the class. Therefore, it is also called data hiding.

Let’s understand Encapsulation in java better by taking real-time examples.

 

Realtime Example of Encapsulation in Java

Example 1:

Schoolbag is one of the most real examples of Encapsulation. Schoolbags can keep our books, pens, etc.

 

Example 2:

When you log into your email accounts such as Gmail, Yahoo Mail, or Rediff mail, there is a lot of internal processes taking place in the backend and you have no control over it.

 When you enter the password for logging, they are retrieved in an encrypted form and verified, and then you are given access to your account.

 You do not have control over it that how the password has been verified. Thus, it keeps our account safe from being misused.

Example 3:

Suppose you have an account in the bank. If your balance variable is declared as a public variable in the bank software, your account balance will be known as public, in this case, anyone can know your account balance. So, would you like it? Obviously, No.

So, they declare the balance variable as private for making your account safe, so that anyone cannot see your account balance.

The person who has to see his account balance, will have to access only private members through methods defined inside that class and this method will ask your account holder name or user Id, and password for authentication.

Thus, we can achieve security by utilizing the concept of data hiding. This is called Encapsulation in Java.

 

How to achieve or implement Encapsulation in Java

There are two important points whereby we can achieve or implement encapsulation in the Java program.

1. Declaring the instance variable of the class as private. so that it cannot be accessed directly by anyone from outside the class.

2. Provide the public setter and getter methods in the class to set/modify the values of the variable/fields.

 

Advantages

There are the following advantages of encapsulation in Java. They are as follows:

1. The encapsulated code is more flexible and easier to change with new requirements.

2. It prevents the other classes to access the private fields.

3. Encapsulation allows modifying implemented code without breaking other code that has implemented the code.

4. It keeps the data and codes safe from external inheritance. Thus, Encapsulation helps to achieve security.

5. It improves the maintainability of the application.

6. If you don’t define the setter method in the class then the fields can be made read-only.

7. If you don’t define the getter method in the class then the fields can be made write-only.

 

A disadvantage of Encapsulation in Java

The main disadvantage of encapsulation in Java is it increases the length of the code and slows shutdown execution.

 The history is full of stories about the great
inventions of man-kind. These are the inventions that now make our life easier as
well as convenient. But some of these came into existence accidentally. Despite
that they made a huge change in fields of science and also our life-style. Below
is six- great inventions that were accidentally invented.

Saccharin-Artificial sweetener

 Constantin Fahlberg,
a Russian chemist, was working in his lab right after which he went to have sandwiches
without washing his hands. He realized that the usual sandwich is sweeter. Upon
realizing that he discovered that his hand was covered with the compound,
benzoic sulfinide, formed after reaction of o-sulfobenzoic acid with phosphorus
chloride and ammonia is the one he tasted. Under different circumstances this
could have been a health hazard, but luckily he invented something edible.

Pace maker

Wilson Greatbatch, a professor of engineering at the
University of Buffalo, in the year of 1956 accidentally invented the pacemaker.
He was working on building a device that would record the heart beats and ended
up finding the device is giving off electric pulses, similar to that of a heartbeat.
Later Greatbatch then introduced his invention to a surgeon, William Chardack, with
whom he was to successfully abled control a dog’s heartbeat. And after few
years, in 1960, it was able to work on humans too.

Penicillin

One of the man-kinds best invention, Penicillin was invented
on accident. In the year of 1928, DR. Alexander Fleming left out his culture
Staphylococcus aureus in his lab two week. He was about to throw it away before
finding that its growth had being prevented by the mold called Penicillium
notatum. From there he isolated the mold and ran tests to determine that penicillin
has antibacterial effect on staphylococci and other gram-positive pathogens.

Champagne

The monks of the champagne, having the best access to
grapes, decided to make white wine. Since it was cold it hindered the fermentation
process and when the spring came, wine containers were filled with carbon
dioxide. The excess of carbon dioxide caused carbonation in the drink. To fix
this, French monk named Dom Pierre Perigon came over to champagne handle it. But
later people decide that the carbonation made the drink fizzy and hence tastier.

Popsicles

When Frank Epperson was 11-years old, he mixed some
soda power with water and left it in the freezer overnight completely by
accident. The next day he decided to lick the frozen soda solution and was delighted
by its taste. The young boy originally named it as ‘epsicle’, combining icicles
and his name, but later he changed it into what we know it as popsicles.

Superglue

Harry Coover, in the year of 1942, was searching for a
material that he could use to build clear plastic gun sights for the war, but
ended up with a chemical substance that would stick to everything it made
contact with. Despite that, his invention was rejected since the researcher
didn’t find any use of the sticky substance. Later in the 1951, the formulation
was innovated by Cooper and Fred Joyner as ‘alcohol-catalyzed Cyanoacrylate
Adhesive compositions’ or as we know superglue. And from the on the superglue
was embraced as one of the most useful invention.

 Have you ever wondered how pi was calculated before Newton
discovered it. Up until the 250BC, mathematicians knew for a fact that the
value of pi is between 3 and 4. And you may ask that how did they know that,
the answer to that would be that they did that with the help of a hexagon and
square.

A unit circle (area = π)
was inscribed with a regular hexagon of unit sides. And the circle was inscribed in a
square. The hexagon was then further divided into 6 equilateral triangles with
unit sides. Then the perimeter of hexagon was found to be 6 units. Since the
hexagon was inside the circle the circumference of the circle must be a little more than
that of hexagon.

Circumference > perimeter

2 π > 6

π >3

On the other hand, the perimeter of square > circumference of the
circle.

2 π<8

π <4

Hence, it was concluded to be between 3 and 4, i.e, 3< π<4.

Later in the 250BC, Archimedes improved this calculation. He bisected
the hexagon into a dodecagon (12 sides) and inscribed one into the circle and inscribed
the circle in another 12-sided polygon. After calculation, it was found that π
lies between 6.212 and 6.431. This process repeated for centuries until they
reached the 96-sided polygon and found a range of 3.1408< π<3.1429.

In the late 16^th century, Francois Viète
doubled a dozen times than Archimedes and computed the perimeters of polygon of
393,216 sides. And by the early 17^th century, Ludolph van Caulen surpassed
him by calculating perimeter of polygon of 2^62 sides. He spent 25 years of his
life calculating π upto 35 correct decimal places.

People were used this method of computing pi until Sir Newton came along.
The first step to his discovery of π was building Binomial theorem from the
Pascals triangle. Sooner after he also delt with the theorem being subjected to
incompetency when power of (1+x) was -1, since it would give an infinite
series. But he proved its accuracy by multiplying both sides by (1+x). The left
hand side gave 1 straightaway and when (1+x) was multiplied on the right hand
side, every term got cancelled leaving only one.

Afterward he went for (1+x) with power of ½ to solve for the area of a
unit circle by equation of the circle, which was given by x^2+y^2=1. Hence, the value y=(1-x^2)^1/2 can be calculated by substituting the value of x by -x^2.

Right after this, he also invented calculus. And the integration from 0 to 1
was used to find the area under y=(1-x^2)^1/2 which is the area of the quarter of
circle in the first quadrant. We also know that the area of quarter of circle
is (πr^2)/4. In this case it will be π/4 (since r=1). Upon equating them and calculating we get
the value of π. To make things easier and accurate he decided to integrate from
0 to ½. It gives the area of the circle from the left of y axis to the straight line of
x=1/2. That area can be calculated as area of a sector of 30 degrees, which
will be π/12, and a right triangle of sides 1 and ½ ( we can calculate the
third by Pythagoras).

And upon equating we once again can find the value of π. Not only that
but when you solve up to 5 places of the integration, you get results π for up to 5 decimal places. And it
will take calculation of integration up to 35 terms to get what Ludolph
van Caulen got after 25 years. This is how years of calculation was simplified
by Sir Isaac in a way it took only a few days to learn the value of pi.

SOURCE- Veritasium on youtube

You must have seen several talent-shows where people
would guess the day of a given dates. Some of you must have thought they do it
by memorizing the entire calendar. Well, it somewhat does require memorizing,
not the entire calendar though, and the rest is basic calculation. Let’s jump
right into it.

 The method that
we are gonna discuss about is called Doomsday Rule. This algorithm was devised
by John Conway, inspired by Lewis Carroll’s perpetual calendar algorithm, in
the year 1973. By using this method anyone can calculate the day of any date in
any given year.

In this method one need to remember these special
dates also known as doomsday, these days include:

4/4,6/6,8/8,10/10, 12/12, 7/11,11/7, 9/5,5/9

[ Note- Every dates in this article are in the format
of month/day/year]

The date for the month of January and February differs
according to the leap year.

The special dates of January are the 3^rd
and 4^th (for leap year) and for February, it is 28^th and 29^th
(leap year). So, it is 1/3 and 2/28 for three years and ¼ and 2/29 the other.

For March, the special date is the pi day, that is,
3/14.

Other notable special dates are 10/31- Halloween and
12/26- boxing day.

Now, one may ask what’s special about these dates, to
that, these days in a given year appears on the same day. For example, if you
know the 12/12 is Friday, then the rest of the dates mentioned will also be on Fridays.

Now that we know the trick let’s learn about how to apply
them. For example, let’s find out the day of 11/26/2023.

For every question we need a reference date, which
could be any of the doomsday. For this case let’s take the pi day as the reference.
Once we know about pi day we will automatically know about the rest of the days.
And that’s when we face the question that how do we know that. There is a
simple trick to that as well. All you need to remember is that the pi day was a
Tuesday in the year 2000.

2000 – Tuesday

2001- Wednesday

2002- Thursday

2003- Friday

2004- Sunday

As you can see, that every year the day increments by
one and in the leap year it is incremented by 2.

When you need to find out about past dates, those of
before 2000, all you need to remember is this pattern,

1700- Sunday

1800- Friday

1900- Wednesday

2000- Tuesday

And this pattern repeats, which means 2100 pi day
would be on Sunday, 2200 on Friday and so on.

Now let’s get back to the question. So, the year is
2023. We know on 2000 pi day was in Tuesday, all we gotta do is add the number
of years plus the number of leap years to Tuesday,

Tuesday + 23 + 23/4(=no. of leap years)

Tuesday + 23 + 5 (ignoring the decimal, which is to be
done in every case, since years can’t be in decimal)

Tuesday + 28= Tuesday (*since 28 is a multiple of 7)

(*when days are added with numbers which 7 or multiple
of 7, you would get the same day)

So, pi day in 2023 is a Tuesday. After this step you
need to find the nearest doomsday to the date in question. Here, it would be
11/7. 11/7 is also Tuesday. To find 11/26 we gotta add

Tuesday + (26-7) = Tuesday + 19 = Sunday

Hence 11/29/2023 will be a Sunday.

You can go to the calendar and check if the results
are correct. You can try this method on any date and year and see it for
yourself.

Algebraic expressions that we see and encounter today
is way different than it was centuries ago. Until 19^th century, they
consisted of theories. The father of algebra Muhammad ibn Musa al-Khwarizmi
described algebra to be reduction and balancing of terms that is a
transposition to other sides of the equation. Algebra went through different
stages to development along the centuries. Along which the three stages that
gives us the history of symbolic algebra are to be discussed in this article.

1. RHEOTORICAL STAGE

In this stage, the algebraic expressions were written in
sentences. For example, an equation as: x+ 24= 36 would be described as
‘something added to 24 gives us 36’. It was developed by Babylonians back in
the 16^th century.

2. SYNCOPATED ALGEBRA

In this stage, the symbolism was used but it didn’t
contain all of the characteristics of symbolic algebra, there were some
restrictions involved. Syncopated algebra made its first appearance in the 3^rd
century AD through Diophantus Arithmetic, followed by Brahmgupta’s Brahma
Sphuta Siddhanta back in the 7^th century.

3. SYMBOLIC ALGEBRA

Symbolic algebra made its appearance through Islamic
mathematicians such as Ibn al-Banna in 13-14^th centuries and
al-Qalasadi in 15^th century in their works. And it was fully
developed by Francois Viete in the 10^th century. Later, Rene
Descartes by 17^th century, introduced the use of ‘x’ in an equation.
He also showed that problem in geometry can be expressed and solved in terms of
algebra. Quadratic equations played an important role in early algebra and it
is to be noted that earlier only three types of quadratic equations existed:

x2
+px=q

x2
=px+q

x2
+q=px

Since math was used in commerce there were no use of
negative terms. ‘p’ and ‘q’ was positive in each of the above cases and so were
the roots.

On to most interesting part where mathematical
expressions were solved with geometric practices. Between the rheotorical and
syncopated stage of symbolic algebra, the geometric constructive algebra’ was
developed by classical Greek and Vedic Indian Mathematicians in which equations
were solved through geometry.

Now let’s look at this equation:

x2
+26x=27

Since we already know how to find roots of quadratic
equation, i.e. by using,

x=-b±√(b2 -4ac)2a

As they didn’t consider the negative part, let us
exclude that and put the respective values, we will get

x=-26+262 -[4×1×(-27)]2×1

x=-26+(676+108)2

And now let’s solve it with the help of figures. Taking
the x^2 as a square of side x and thus the term gives its area.
And the 26x can be denoted as rectangle with sides 26 and x and the term being
the area.

Now, if we divide the rectangle into two equal parts
which will give us two rectangle of side x and 13.

By placing the rectangles on two adjacent sides of the
square, we will see a L shaped figure which can we converted into a square if
we added a square of side 13 in the space.

And since we added a square, we now have to add 169, which
is the area of the additional square, on each sides of the equation. It gives
us

x2
+26x+169=246

 The left-hand
side of the equation represents the sum of areas of the 2 squares and 2 rectangle
and the right-hand side gives the total area. Since all the shapes collectively
makes a square, the number 246 denotes the area of the biggest square. And hence
14 will be the length of the sides. And now we know that the value of x must be
1.

While this method will only work on positive
entities and will only give the positive part of the solution, we can now see the quadratic equations from a whole new perspective.