Curso Java. Estructuras principales VI. Clase Math. Vídeo 9

Summary

Este curso de programación en Java, dirigido a principiantes, aborda conceptos fundamentales como las estructuras de datos y las clases. Se explica cómo realizar operaciones matemáticas avanzadas utilizando la clase Math, incluyendo raíces cuadradas, potencias y redondeo. Se introducen las clases predefinidas y personalizadas en Java, y se enfatiza la importancia de la API de Java para acceder a cientos de clases y métodos. El vídeo también explora cómo utilizar el método sqrt() para calcular raíces cuadradas y resalta la precisión de Java con tipos de datos, utilizando Eclipse para demostrar la creación y ejecución de un programa simple.

Takeaways

• 😀 Este curso de programación en Java aborda la creación de programas desde cero.
• 🔢 Se ha discutido cómo declarar variables y constantes, así como los diferentes tipos de datos en Java.
• 🧮 Se exploraron los operadores aritméticos básicos como la suma, la resta, la multiplicación y la división.
• 📚 Se avanzó en el conocimiento de las estructuras principales y se introdujeron cálculos numéricos más avanzados como raíces, elevado al cuadrado y redondeo de números.
• 👨‍🏫 Se enfatizó la importancia de las clases en Java, tanto las propias como las predefinidas, y se explicó la diferencia entre ellas.
• 📚 Se mencionaron clases predefinidas en Java, como String, Math, Array y System, que facilitan tareas comunes en la programación.
• 🔍 Se presentó la API de Java (Java API) como una herramienta esencial para consultar clases y métodos predefinidos.
• 💻 Se utilizó Eclipse para demostrar cómo se programa en Java y se abrió un nuevo espacio de trabajo para crear una clase llamada 'Calculations'.
• 🛠️ Se explicó el uso del método sqrt() de la clase Math para calcular la raíz cuadrada de un número y se corrigió un error de tipo de datos.
• 🔄 Se mencionó que se abordará el uso del método round() y la técnica de recast en futuras lecciones.

Q & A

¿Qué temas se abordan en el curso de programación en Java mencionado en el guion?

El curso aborda la declaración de variables, tipos de datos en Java, operadores aritméticos, y avanza hacia el uso de la clase Math para realizar cálculos numéricos avanzados como raíces cuadradas, elevar a una potencia, redondeo de números, entre otros.

¿Qué es una clase en el contexto de programación en Java?

Una clase en Java es una estructura de datos que actúa como una plantilla para objetos, puede contener métodos y variables, y es un concepto fundamental ya que todos los programas Java deben estar compuestos por al menos una clase.

¿Cuáles son las dos tipos de clases que se pueden tener en Java según el guion?

Las dos tipos de clases en Java son las clases propias, que son aquellas que el programador crea, y las clases predefinidas, que vienen incorporadas en el lenguaje de programación Java.

¿Qué es la clase Math en Java y qué propósito cumple?

La clase Math es una clase predefinida en Java que contiene métodos estáticos para realizar cálculos matemáticos como raíces cuadradas, potencias, redondeo, entre otros.

¿Qué es la API de Java y cómo se relaciona con las clases predefinidas?

La API de Java es una biblioteca que contiene todas las clases del lenguaje de programación Java, y es una herramienta que los programadores consultan frecuentemente para usar las clases y métodos predefinidos en sus programas.

¿Cómo se puede utilizar el método sqrt() de la clase Math para calcular la raíz cuadrada de un número?

El método sqrt() se utiliza pasando un número como argumento y devuelve la raíz cuadrada de ese número. El resultado es de tipo double, por lo que se debe almacenar en una variable de tipo double.

¿Qué es un error de conversión de tipos en Java y cómo se presenta en el guion?

Un error de conversión de tipos ocurre cuando se intenta almacenar un dato de un tipo en una variable de otro tipo incompatible. En el guion, se presenta un ejemplo donde se intenta almacenar el resultado de sqrt(), que es un double, en una variable de tipo int, lo que causa un error.

¿Qué herramienta de desarrollo se utiliza para ilustrar la creación y ejecución de código en el guion?

El guion utiliza Eclipse, un entorno de desarrollo integrado (IDE), para crear, editar, y ejecutar programas en Java.

¿Qué métodos adicionales de la clase Math se mencionan en el guion para futuras sesiones?

Se mencionan métodos como round() para redondear números, pow() para elevar a una potencia, y la posibilidad de explorar el concepto de recast, que es el cambio de un tipo de dato a otro.

¿Qué es un constante en Java y cómo se relaciona con la clase Math?

Una constante en Java es una variable cuyo valor no puede cambiar después de que se le asigne. La clase Math tiene constantes predefinidas, como PI, que almacenan valores fijos importantes para cálculos matemáticos.

Outlines

00:00

📚 Introducción al curso de programación en Java

El primer párrafo presenta un curso de programación en Java, enfocándose en la explicación de las estructuras principales del lenguaje. Se menciona que se han cubierto temas como la declaración de variables y constantes, así como los tipos de datos en Java. También se recuerda que en el vídeo anterior se exploraron los operadores aritméticos básicos. El vídeo actual promueve avanzar en el conocimiento de estas estructuras, introduciendo cálculos numéricos más avanzados como raíces, elevación al cuadrado y redondeo de números. Se destaca la importancia de estas habilidades para los programadores principiantes y se anuncia la exploración de la clase Math en Java para realizar estos cálculos.

05:02

🏫 Importancia de las clases en Java y la biblioteca de clases (API)

El segundo párrafo profundiza en el concepto de clases en Java, explicando que todo programa en Java debe estar compuesto por al menos una clase y que los programas suelen estar compuestos por múltiples clases. Se diferencia entre clases propias, que son aquellas que el programador crea, y clases predefinidas que vienen incorporadas en el lenguaje. Se ilustra con ejemplos como la clase String para manejar cadenas de caracteres y la clase Math para realizar cálculos matemáticos. Además, se introduce la API de Java como una biblioteca de clases y métodos que el programador puede consultar y utilizar en sus programas.

10:03

🔢 Explorando la clase Math y sus métodos matemáticos

El tercer párrafo se centra en la clase Math y sus métodos para realizar cálculos matemáticos. Se mencionan métodos como sqrt para calcular raíces cuadradas, pow para elevar un número a una potencia y otros métodos para funciones trigonométricas como sin y tan. También se habla sobre el concepto de redondeo y la existencia de constantes predefinidas como PI y E. Se enfatiza la importancia de manejar la API de Java para aprender y utilizar estos métodos en la programación.

15:06

💻 Creación y errores en la programación con Java

El cuarto párrafo describe el proceso de creación de una clase en Java y la ejecución de un ejemplo simple para calcular la raíz cuadrada de un número. Se detalla cómo se declara una variable y se utiliza el método sqrt de la clase Math, pero se comete un error al intentar almacenar un valor decimal en una variable de tipo entero. Se explica la rigidez de Java con los tipos de datos y cómo el editor Eclipse ayuda a identificar y solucionar estos errores, proporcionando información sobre los métodos y sus tipos de datos esperados.

20:06

✅ Solución de errores y uso de la clase Math en Java

El último párrafo concluye con la corrección del error mencionado anteriormente, cambiando el tipo de la variable para almacenar el resultado decimal de la raíz cuadrada. Se muestra la ejecución del programa y el resultado esperado, que es el número 3.0. Además, se anuncia que en futuros vídeos se explorarán otros métodos de la clase Math, como el redondeo y el uso de métodos con dos parámetros, así como el concepto de recast para cambiar un tipo de datos a otro.

Keywords

💡Clases

Las clases son una de las estructuras fundamentales en la programación orientada a objetos, y en el vídeo se menciona que cada programa en Java debe estar compuesto por al menos una clase. Las clases en Java pueden ser propias, que son aquellas que el programador crea, o predefinidas, que son proporcionadas por el lenguaje de programación. En el vídeo, se utiliza la clase 'Math' como ejemplo de una clase predefinida para realizar cálculos matemáticos, destacando así la importancia de las clases en la estructura y funcionamiento de los programas Java.

💡Variables

Las variables son elementos utilizados en la programación para almacenar datos. En el guion, se habla sobre cómo se declaran variables y constantes, y se menciona que en Java se tienen diferentes tipos de datos para dichas variables. Las variables son fundamentales para almacenar y manipular información dentro de un programa, como se ve en el ejemplo donde se declara una variable para almacenar el resultado de la raíz cuadrada de un número.

💡Operadores aritméticos

Los operadores aritméticos son símbolos que representan operaciones matemáticas básicas como la suma, la resta, la multiplicación y la división. En el vídeo se menciona que en el vídeo anterior se vieron cómo usar estos operadores para realizar operaciones simples, lo que es esencial para el procesamiento de cálculos en cualquier programa.

💡Raíz cuadrada

La raíz cuadrada es una operación matemática que se utiliza para encontrar un número que, multiplicado por sí mismo, resulte en el número original. En el vídeo, se utiliza el método 'sqrt' de la clase 'Math' para calcular la raíz cuadrada de un número, mostrando cómo se puede realizar este cálculo en Java y resaltando la precisión de los tipos de datos al almacenar el resultado en una variable de tipo double.

💡Tipos de datos

Los tipos de datos son categorías predefinidas de valores que una variable puede almacenar. En el vídeo se discute la importancia de los tipos de datos en Java, como enteros (int) y dobles (double), y cómo se deben utilizar correctamente para evitar errores de conversión, como el intento de almacenar un resultado decimal en una variable de tipo entero.

💡Métodos

Los métodos son bloques de código que realizan una tarea específica y se pueden reutilizar en diferentes partes de un programa. En el vídeo, se mencionan varios métodos de la clase 'Math', como 'sqrt' para calcular raíces cuadradas y 'round' para redondear números, demostrando cómo estos métodos facilitan el desarrollo de programas al encapsular funcionalidades comunes.

💡API de Java

La API de Java es una biblioteca de clases y métodos predefinidos que permite a los programadores utilizar funcionalidades avanzadas sin tener que programarlas desde cero. En el vídeo, se hace referencia a la API de Java como una herramienta esencial para los programadores, ya que incluye cientos de clases y métodos que pueden ser consultados y utilizados en los programas.

💡Eclipse

Eclipse es un entorno de desarrollo integrado (IDE) ampliamente utilizado para la programación en Java. En el vídeo, se utiliza Eclipse para crear y ejecutar un programa que utiliza la clase 'Math', mostrando cómo los IDEs facilitan la escritura, la compilación y la depuración de código, y cómo proporcionan ayuda para la programación, como sugerencias de métodos y autocompletado.

💡Errores de conversión de tipos

Los errores de conversión de tipos ocurren cuando se intenta almacenar un tipo de dato en una variable que no es compatible con ese tipo. En el vídeo, se muestra un ejemplo de este error cuando se intenta almacenar el resultado de la función 'sqrt', que devuelve un double, en una variable de tipo int, lo que provoca un error hasta que se corrige el tipo de la variable a double.

💡Constantes

Las constantes son variables cuyos valores no pueden cambiar una vez que se han asignado. En el vídeo, se menciona la constante 'PI' de la clase 'Math', que almacena el valor de pi, una cifra matemática fundamental en la trigonometría. Las constantes son útiles para mantener valores inmutables que se utilizan a lo largo de un programa.

Highlights

Bienvenido a otro entrega de curso de programación en Java.

Se discute la importancia de las estructuras principales en Java.

Se explica cómo declarar variables y constantes en Java.

Se exploran los tipos de datos en Java.

Se enseña el uso de operadores aritméticos para realizar operaciones básicas.

Se avanza en el conocimiento de las estructuras principales y se mencionan otros cálculos numéricos.

Se mencionan cálculos como raíces, elevados al poder y redondeo de números.

Se habla sobre la necesidad de conocer el manejo de la clase Math para realizar cálculos en Java.

Se aclara la diferencia entre clases propias y clases predefinidas en Java.

Se explica que cada programa en Java debe estar compuesto por al menos una clase.

Se menciona la importancia de la clase Math para realizar cálculos matemáticos en Java.

Se presentan ejemplos de clases predefinidas en Java, como String, Math, Array y Thread.

Se habla sobre la imposibilidad de memorizar todas las clases y métodos predefinidos y la necesidad del API de Java.

Se muestra cómo se puede consultar la biblioteca de clases de Java (API) en línea.

Se discute la importancia de las clases y sus métodos en la programación en Java.

Se explica cómo se pueden utilizar métodos de la clase Math, como sqrt para calcular raíces cuadradas.

Se menciona el uso de la constante pi en la clase Math para cálculos trigonométricos.

Se ilustra cómo se puede encontrar y utilizar métodos de la clase Math con la ayuda del IDE Eclipse.

Se da un ejemplo práctico de cómo se declara una variable y se le asigna el resultado de una operación matemática utilizando la clase Math.

Se explica el error de tipo de conversión y cómo solucionarlo al utilizar métodos que devuelven un tipo de datos específico.

Se muestra cómo ejecutar un programa simple en Eclipse que utiliza la clase Math para calcular la raíz cuadrada de un número.

Se invita a los espectadores a seguir el curso para aprender más sobre el uso de la clase Math y otros conceptos en futuros videos.

Transcripts

hello that such welcome to another delivery

this java programming course from

zero we were watching in videos

previous main structures

of language we have already seen how

declare variables like declare

constant we talked about the types of

data in java and in the last video if

you remember, we were seeing how

use the arithmetic operators to

do simple operations such as

sums subtraction multiplications and

divisions in this video we follow

advancing in the knowledge of

main structures and let's see

how to perform other numerical calculations

in java

when we say other numerical calculations

we refer for example to roots

square we mean to raise a

number to a power rounding of

numbers and so on

and to do these calculations that are

essential when programming

maybe those who are starting in the

world of programming because you can not

see the need to learn to do

all this when creating a program

but I already anticipate that it is

essential and to be able to do these

calculations in java we have to know the

handling of the class more and that is it turns out

that to make these calculations we must

use in java this class the term

of class because maybe we still find

everything familiar maybe serves us a little

because we are starting to program in

java we are not in the beginning yet

that we know about the classes that we know

of the class concept as we said in

previous videos all java program

must be composed of at least one

class as usual is that a program in

java is composed of more than one class

but at least it has to be formed of

a class and we the examples that

We have been doing so far

they have been composed of a class not

we have to keep moving forward in this

class concept although not yet

we are in a position to deepen

everything you need but

we have to know at least two things

and is that besides that every program

java has to be composed at least

of a class the classes in java can

be of two types we can have in java

own classes and we have in java classes

predefined what is the difference between

one and the other

own classes are what we create

us as we have done then in

previous videos for example now

we have one of the classes on screen

what we did in the last good video

because this would be a class of its own is a

class that we have created very

simple and this class has a unique

method another term that still does not

we control completely the method that has

this class is the main all class method

in java all program in java must have

at least one main method unless it is

a play program that we already talked about

it at the time in the applets it

replace the main with the line method

but good for the moment this is not us

worry we'll see later

these are the classes that we have

gone so far very simple

Well, these are our own classes

classes developed by us

however we also have another kind of

classes that are the predefined ones and these

they are classes are already built inside

of the java programming language are

classes that are supplied with the

programming language so that

we can use in our programs

in the case that we need them and here

in this little graphic I have put you

four examples of predefined classes

that come in java and I tell you that I have

put only four examples but

come hundreds and hundreds that is to say to the

time to program in java us

we have hundreds and hundreds of classes

predefined that is already built

so that we can use them in

our programs if we need them

the examples that I have put in this

screen are the string class that

we have not seen it yet, it's good for

handle character strings strings

text the class more that is then the one that

let's see a little bit above in this

video which allows us to make the

mathematical calculations square roots

round powers and so on

the array class which is another one of those

we will manage throughout the course

the array class allows you to manipulate

handle arrays

arrays and then then we have the class

create that is another class that is used

quite when it comes to programming in java

and that allows

the concurrent programming that is called

but I've put four examples

of four of the most used classes

but as I say there are hundreds

so many are the classes that there are for

a programmer is impossible to memorize

all and not just memorize the

classes keep in mind that each class

predefined that comes with the language

java brings with it a number of methods

who perform different tasks with what

what if it is impossible to memorize all the

classes is even more impossible is to memorize

the methods that come with those classes

so that we can use them is because

what exists in java what is known

as a class library or

called api de java which is the pija

well, the blackboard is a library

where all the classes of the

java programming language and that all

programmer should consult with

often when preparing a

program since it is very likely that

example if you frequently use the

class more you forget it then some of

the methods that come within that

class you know that they exist but you do not

remember its syntax do not remember

of the arguments that come in that

method and you'll have to consult the

library

this library is very easy to use

to her and let's see an example I'll

open a browser for example firefox

previously

and once we open firefox firefox

sorry if you go to the google page

Well, in any search engine if you

you say to fix to fix that I do not

I have purple because the consultation with

often the first link that we

it offers then it is a link to the java app and

here it left library of classes not

so if we click on that link then

right now we have open what is the

java class library not yet

we are in a position to handle this

class library because this

class library you also have to

learn to manage it is composed of

different panels or parts that

we will talk about them at the time without

However good in this panel that

we have here below to the left then

they come in alphabetical order all the

classes that we currently have in the

java programming language and fixes

that as I told you there are one hundred 600 there is no

human person able to memorize all

these predefined classes that come with

the language so that we can

use

As I said before, there are classes that

commission calculations

mathematicians like most there are classes that

They are in charge of carrying out operations with

strings of characters like string there

classes because they are dedicated to work

with networks there are classes that are dedicated

to the graphic part for example having

here then green bay the youth good

all this refers to work

java graphic is to say if you want

create the graphical interface as you will have

that working with these classes here is

the same graphics class serves to

work with graphics in java graphics

from finally hundreds and hundreds of classes

Each class as I say has its own

methods and you will find out right now

those who did not know it before the

dimension of the programming language

java is to say the number of classes

predefined methods packages that already

We will see at the time what it is that

they come with this programming language

as of today, May 19, 2014 that

is when I'm recording this video the

app and it goes by version 7 what do you want

say this

well, it means that we

When installing a machine

virtual of the java

we've talked about it in videos

previous we are installing us the

version 7 with time then surely

that instead of installing version 7

we have to install version 8 and

in a couple of years with surely

let's be by version 9 by the version

10 is not to say the virtual machine of

java that we have installed in this course

It updates what the

update of the virtual machine

java because it consists of several things and a

of them is that more classes are included

that is, in this class library

right now the classes that exist are

these are the classes with which

We currently have to program in

Java

but over time new

you already know that information technology

evolves constantly and

programming languages also with what

what if a need arises

which requires the use of a calculation of a

class or whatever it is that right now

What you do is update the

java virtual machine instead of the

version 7 as they update it to 8 as

consequence the library is updated

of java classes is to say the api of

java is updated and include those classes

new ones that allow you to do these

news

that have been emerging over time is

the library of the left was fixed

constantly updated with which

There are many people who download it

because it is possible to download the

java library in local to have it

on your hard drive and well this download

Well, he's consulting it but I'm going

I recommend if you have an internet connection

it is to consult the online route because

If you consult online, you can be sure

that you're always updated

you know that java belongs to oracle with

which is good as the download or the

consultation is done from the page of

prayer said this

well then we go back to our

power Point presentation

and we already have a slight emotion of what

which is a predefined class not

worry that we will go deeper

course in the use of the sabín apa

api sorry or library of classes and in

this video what we are going to do is see

a little a little bit more the class more

because the class has a lot more

methods for doing mathematical calculations

and I'm just going to mention the

main calculations obviously if

you learn to use the class more for

do basic or usual calculations and

you also learn how to handle the api

java that we will see in future videos and

also already shortly

you will know how to use any method

belonging to the class plus or

belonging to any other kind of

java what methods are we going to see us from

the best class because the methods that

let's see from the matt class are more

point s qr t is to say the method s cub rt

what he does then is to return us a

decimal number

is the square root of the parameter

specified in parentheses in

definitive

point that is what is allowed

calculate the square root of a number

the method for what it does is calculate the

power of a number this method receives

two parameters or arguments a base and

an exponent

we are also going to use good this is not

we are going to use drinks or mentioned

more points and what it does is calculate the

sine of an angle plus a total what

does is calculate the tangent to so

the tangent arc is to say as you can

observe the class more

what it brings inside are diverse

srt methods all without cause so tan and

many others to do calculations not

round method what it does is round a

this number is used a lot is not

very frequent that the need arises

round one figure at the time of

work then in a java program and not

there is also the concept of constants

of class then we have already

seen what is a constant but we have

seen what is a constant itself is

say we have learned to declare a

constant in our own

we know that the value of a constant does not

can change as we have classes

own and predefined classes as per

example more we also have constants

own those that we have seen in videos

previous and predefined constants or

class constants

the constant predefined constants

of class are those that accompany the

class is to say they come with the class and what

what they do then is store in their

internal values that can not be

modified for example is very common

than to do trigonometry calculations

you need to use the number and then

the pi number because everyone I think we know

which is equal to 3 1416 rounding off

well, this is a fixed value

value of the number pi can not change

under no circumstances the number that

it has to be always the same is because

this reason why it is stored in

a constant constant that has

called and and as a consequence of this

we can use it and the type value

you can not change it a constant of

class

and all this as it translates to the

good practice then let's open

eclipse below and let's see

how to use the map class to perform

this series of basic calculations so

as always because we are going to close the

presentation of power point and we are going to

open the eclipse program

then then we go to the folder

where we have stored the program

we double click on the executable and

we wait for the program to load

you know it takes a few moments once

that the program loads well since it

usually open for the class you left

open is to say if at the time of closing

eclipse you left an open class like

is my case saved changes but

open is to say on the screen well

Eclipse is usually opened by that class

we remember that in the browser

packages because we have our project

which we call first steps

Within our project we have the

source src folder and inside we have

the default package something that is not yet

we know very well what is our

package and we have built at the moment

three classes well then let's build

a fourth class where we use the

best class because you know you can

leave open if you have the same as me

open class you can leave it open

because eclipse what it does is work

by tabs that is to say as you go

creating classes and leaving them

open as they appear

continuation of the previous

and if you want to work more

comfortable you can close the class from your

corresponding X and create a new

is to create a new class you know

what can be done from different

menus and buttons I'm going to use the

button on the toolbar and you

I'm going to say that this class is going to

call for example

calculations and a bass with more and I'm going to

say already to the creation window of

classes that create the main method and so

Well, we already have part of the work

done and then as always since we're going to

enter within the mail method no

this would be an example of the class itself

because it is a class that we have created

us right now and it's called

calculations commas well let's go to

use the sea class so you can see

what would be the mechanics

let's create a simple instruction

that allows us to find out the root

square of a number but I'm going to

do to start badly and I'm going to do it

bad so that you can see where the

error and see also how strict it is

the java programming language with the

data types then I will declare

an integer variable where

I intend to store the result of

the square root of a number then

Well I say int

then name of the variable

Well, I'm going to call you, for example, the root

we can call as we want and tell him

that this will be equal to more

point and then the method would come

but before putting the method that

we remember that to find the root it was s

qr t fix that eclipse it helps us

quite at the time of writing with these

menus of which we have spoken in

previous videos the behavior

smart when we put more

point a menu is displayed in which

all methods appear

that belong to the class plus all the

methods and also look at the impossible that

is to memorize this in addition to the methods

the constants also appear

predefined that come with marc and here

appears for example the constant and the

that we talked about a moment ago but

another number also appears

constant that is the number e that also

has a fixed value not good when

I put and I remove the zoom I'm going

but also notice that eclipse

offers us another help and is that

example if we are going to use that

qr t if now after the point

we write an s this menu is going to all

the methods that start with that and already

we are seeing in this menu well where

you find that q rte not

Well, if in addition to one you put a quota

we already have only the srt method and

here we are given a lot of information and

this makes it eclipse look at us

saying eclipse in this submenu that

appears on the right that you press the

Tab key to put the focus on

this window

what is the use of that window that we

informs this window good because this

window informs us of what it is that

does the method that does not have what

what to work with an editor of these

features like eclipse netbeans

etc. helps a lot at the time of

program it is also convenient

convenient I do not consider it

fundamental that when programming

in java you have always, although not what

we know use still minimized the

app and left the class library

a whole programmer java then

normally normally works with the

app and minimized because in this app and

also in the lower left window

we can arrive are ordered by order

alphabetical to the class more and when

let's see the class more notice that the

I'm seeing here if we click on it in

the window on the right so what we

appears from to press as it is a

very exhaustive information of what is it

who does this class and what is it for and

in addition all the methods belonging

to the class and well then what kind of

data returns how it is built

etcetera we are not yet in

willingness to understand this at all

you worry we will be working with it

little by little but well we also have

the help of the eclipse as we have seen

a moment ago if you look at this

menu that comes out in eclipse is us

saying that this method that q rt

receives a parameter or argument that

it has to be double type and this

appears here below informs us

of the type of data returned by this

method is to say this method what does

is to find the square root of a number

well that square root what

it has to be double it is to say it's a

double type data however if you

you see, I'm telling you that I

store the square root because still

we do not even have it done that we

store it in a whole type number

this is going to give an error because the method

s qr returns a double a decimal if

we tell you to keep it a whole not

it is possible with which if we finish

to complete

the square root for example 9

Well, this has to give us a

error notice that in this case eclipse

it will also do it to any other editor

Java programming does not emphasize the

red the instruction and we see a

information balloon to the left if

you place the mouse on top of that balloon

information because it tells us that there is a

Type conversion error and the case

is that you can not convert from double to

whole and that's because the method s qr you

what it does is return an integer if

you also set the internal parameter

It must be a double and we

however we have introduced an integer is

say in the help he told us the method

srt had to have here a double this

what the help told us and yet

the number that we have entered inside

of the arguments of this function is not

a double is an integer really what

is doing hub although we do not

let's see is to consider that number as

you see now on screen 90

we can also put for example the

square root of 952 this is

perfectly valid is a double the

error is that we can not

store it within a whole solution

I'm going to leave the 9 again, well, the

solution is to change the data type to

corresponding type is to say do not tell me

warehouses in a whole number but

they store it in a variable forgiveness or

in a number he stores it in a

variable of double type fixes that in

how much do we change the type of the variable

where we are storing the result

that you already know is 3

Well, automatically disappears

underlined red and the only thing that appears

now it is the information in yellow that

we have seen on other occasions for

tell us that that variable is not yet

used the only thing we would have to

do now it is because of the instruction

system or print

well print

root in the console and our program already

would be finished that is to say statement

variable initiation we are

starting at the square root of 9 and

then we tell him to print us in

the console the value you have stored

in the root variable if we execute this

program then in the console you have to

exit 3.0 and have to exit 3.0 the root

square of 9 stress because the result

that always returns this method is

a double with which if we click on the

play then look like in the console

after compiling it will take a

little does it effectively return a

3.0

Well, here you see the use of the class

plus

specifically with the srt method

let's leave this video at the point in

the one that we meet and in the next

video then we'll see how to use the

round method to round up we'll see how

also use the pop method

example to see then an example of

method that needs two parameters and

let's look at also see a concept

which is the recast concept is

change one type of data to another for that

as I say we will see in the next

delivery so as always I invite you to

Stay tuned for the next video

until then it goes well