1. Universidad Técnica de Manabí
Facultad de Ciencias Informáticas
Carrera Ingeniera en Sistema
Asignatura
Ingles
Project of English:
Docente tutor:
Danny Jarred
Integrantes:
Mastarreno Macías Luis Miguel
3ero Semestre “C”
Periodo: Septiembre 2012-Frebrero
2013
2. UNIVERSIDAD TÉCNICA DE MANABÌ
Misión:
Formar académicos, científicos y profesionales responsables, humanistas,
éticos y solidarios, comprometidos con los objetivos del desarrollo nacional,
que contribuyan a la solución de los problemas del país como universidad de
docencia con investigación, capaces de generar y aplicar nuevos
conocimientos, fomentando la promoción y difusión de los saberes y las
culturas, previstos en la Constitución de la República del Ecuador.
Visión:
Ser institución universitaria, líder y referente de la educación superior en
el Ecuador, promoviendo la creación, desarrollo, transmisión y difusión de la
ciencia, la técnica y la cultura, con reconocimiento social y proyección
regional y mundial.
FACULTAD DE CIENCIAS INFORMÀTICAS
Misión:
Ser una unidad con alto prestigio académico, con eficiencia, transparencia y
calidad en la educación, organizada en sus actividades, protagonistas del
progreso regional y nacional.
Visión:
Formar profesionales eficientes e innovadores en el campo de las ciencias
informáticas, que con honestidad, equidad y solidaridad, den respuestas a
las necesidades de la sociedad elevando su nivel de vida.
3. PROGRAMMING IN JAVA
Java language is a general purpose development, and as such is valid for all
kinds of professional applications.
Language Features.
· It is inherently object-oriented.
· Works great networking.
· Leverage features of most modern languages avoiding drawbacks. In
particular, the C + +.
· It has great functionality with its libraries (classes).
The Java language can be seen as an evolution of C + +. The syntax is similar
to this language, so that in this book will refer to the language frequently.
The Java Virtual Machine (JVM)
The Java virtual machine is the idea of language revolucionaria4. It is the
entity that provides platform independence for Java programs "Compiled"
into byte-code.
JDK (Java Developer's Kit)
The basic tool to start developing Java applications or applets is the JDK
(Java Developer's Kit) or Java Development Kit, which consists basically, in
a compiler and an interpreter (JVM) for the command line. It has an
integrated development environment (IDE), but it is enough to learn
language and develop small applications.
Object Oriented Programming
The object-oriented programming is a natural evolution of programming
structured, in which the concept of variables local to a procedure or
function, which are not accessible to other procedures and functions, it is
extensible to own applets that access to these variables. But OOP goes far
beyond.
In object-oriented programming, objects are defined that make up a
application. These objects are formed by a series of features and
operations that can be performed on them.
4. Object
An object is a person, animal or thing. It is distinguished from other
objects by having certain characteristics and "serves" to something, or put
another way, can perform various operations with / on that object.
For example: A house is an object.
FEATURES: Number of floors, Total height in meters Color the facade,
number of windows, door number, city, street and number where it is
located, etc..
OPERATIONS: Build, destroy, painted facade, modify some features, for
example, open a new window, etc.
In terminology of object-oriented programming, the characteristics of
object are called attributes and operations METHODS. Everyone of these
methods is a procedure or a function belonging to an object.
Classes and Objects
In OOP we must distinguish between two closely related concepts, the class
and object.
The way to declare objects in Java is:
Ccasa casa1, house2;
In this case, house2 casa1 and variables are effectively but somewhat
special, are objects. Furthermore, the type of objects is Ccasa.
This type is the kind of object.
Properties must meet a language to be Object Oriented considered.
· Encapsulation.
· HERITAGE.
· Polymorphism.
Encapsulation
Encapsulation is the property possessed objects hide their attributes, and
even methods to other parts of the program or other objects. The natural
way to build a class is to define a set of attributes, in general, are not
accessible outside of the same object, but can only modified through
methods that are defined as available from outside of that class.
class Ccasa {
int nPuertas, nVentanas;
5. String color;
public Ccasa(int np, int nv, String co) {
nPuertas=np;
nVentanas=nv;
color=co;
}
public void pintar(String co) {
color=co;
}
public void abrirVentanas(int n) {
nVentanas=nVentanas+n;
}
public void cerrarVentanas(int n) {
nVentanas=nVentanas-n;
if (nVentanas<0)
nVentanas=0;
}
public void abrirPuertas(int n) {
nPuertas=nPuertas+n;
}
public void cerrarPuertas(int n) {
nPuertas=nPuertas-n;
if (nPuertas<0)
nPuertas=0;
}
}
…
Ccasa casa1,casa2;
…
Heredity
One of the main advantages of OOP. This property allows you to define
descendants of other classes, such that the new class (class descendant)
predecessor class inherits all its attributes and methods. the new class can
define new attributes and methods or attributes can redefine and existing
methods (for example, change the type of an attribute or operations
performed by a particular method).
This property enables code reuse and is very easy to grasp the existing
class code, modifying them to suit the minimally new specifications.
Example: Suppose you have built and want Ccasa class define a new class
that represents the chalets. In this case it may be convenient to define a
new attribute that represents the square footage of garden. Instead of
redefining a new class "from scratch", can written to exploit the class code
as follows Ccasa.
6. Ccasa Cchalet class extends {
mJardin int;
public Cchalet (int np, int nv, co String, int nj) {
super (np, nv, co);
mJardin = nj;
}
}
...
Cchalet chalet1, chalet2;
...
Class Ccasa
nPuertas
nVentanas
color
...
abrirVentanas ()
cerrarVentanas ()
paint ()
abrirPuertas ()
cerrarPuertas ()
class Cchalet
nPuertas
nVentanas
color
mJardin
...
abrirVentanas ()
cerrarVentanas ()
paint ()
abrirPuertas ()
cerrarPuertas ()
As can be seen, only have to declare the new class Cchalet is descended
from Ccasa (extends Ccasa) and declare the new attribute. Clearly, the
7. method must constructor to redefine initialize the new attribute mJardin.
But methods to open / close doors or windows is not necessary .The
constructor is a special method with the same name as the class and whose
function is to initialize the attributes of each object (instance).
Defining, are inherited from class Ccasa and can be used, for example of
the follows:
chalet1.pintar ("White");
Polymorphism
Polymorphism allows a single message sent to class objects different then
these also behave differently (different objects can have methods with
the same name or the same object can methods have identical names but
different parameters).
class Ccasa {
…
public Ccasa(int np, int nv, String co) {
nPuertas=np;
nVentanas=nv;
color=co;
}
public Ccasa() {
nPuertas=0;
nVentanas=0;
color=””;
}
You have two methods with the same name but different parameters. In he
first If attributes are initialized object method parameters and the
second case is initialized to zero, for example. Also, if you have two objects
and chalet1 casa1 and calls the method chalet1.abrirVentanas (2) will run
the procedure code abrirVentanas Cchalet class and not Ccasa class.
Hello, world.
First, let's see what structure should have the typical program which
starts in any programming language that provides a first view of the
language syntax and begins transmitting a series of feelings of acceptance
or rejection by the programmer. the program simply will display the
message "Hello, world" and terminates.
8. class Hello {
public static void main (String args []) {
System.out.println ("hello, world");
}
}
Everything written in Java alone program starts running (as in C) from the
main () method. Classes may be compiled not have main () method, but can
not run Java interpreter initially, but they can run if called from another
running method. We will see in later chapters how creating applets is
different and does not declare this method.
Statement of the main () method:
· Public: indicates that the method main () is public and therefore can be
called from other classes. All main () method must be public to run from
the Java interpreter (JVM).
· Static: indicates that the class does not need to be instantiated use the
method that qualifies. (Not create any instance or Hello class object). It
also indicates that the method is the same for all instances that may be
created.
· Void: indicates that the main function returns no value.
· The main method must always accept, as a parameter, a vector strings
that contain the possible arguments that are passed to program on the
command line, but as in our case, no is used.
The main () method is always declared in the same way:
public static void main (String args [])
Data Types
In Java there are two main types of data:
1) Simple Data Types.
2) References to objects.
The data types are those that can be used directly in a program, without
the use of classes (OOP). These types are:
Byte, short, int, long, float, double, char, Boolean.
9. Data Types reference
All other data types that are not simple, are considered benchmarks.
These guys are basically the classes, which is based programming
object oriented.
Scope of a variable
The scope of a variable is the portion of the program where the variable is
visible to the program code and, therefore, referenceable.
The scope of a variable depends on the location of the program where it is
declared, may belong to four different categories.
· Local Variable.
· Attribute.
· A method parameter.
· Parameter of an exception handler.
Local Variable
A local variable is declared within the body of a method of a class and is
visible only within that method.
Attributes
The attributes of a class are the features to be taken into account on an
object and hence its area is limited, in principle, within the class to which
characterize.
Alternative structures
Alternative structures are structures that allow you to alter the flow
a sequential program so that depending on a condition or value
of an expression, the same can be diverted in either alternative
code.
if-else
Simple:
if (expression)
Block instructions
The statement block is executed if, and only if, the expression (which must
be logic) evaluates to true, ie a certain condition is met.
10. Switch
Simple:
switch (expression) {
case value1: instrucciones1;
case value2: instrucciones2;
...
valueN case: instruccionesN;
}
In this case, unlike the above, whether or instrucciones2 or instrucciones1
instruccionesN are formed by a single block of instructions, it is
parentizarlas required by the braces ({...}).
Loops
Loops are repeat structures. Blocks of instructions that repeat a number
of times while a condition is met or until enforcing a condition.
Loop for
for (initialization, condition, increment)
block instructions
· The initialization clause is a statement that executes a single After the
start of the loop, typically to initialize a counter.
The condition clause is a logical expression that evaluates to top each new
iteration of the loop.
The increase clause is a statement that is executed in each iteration of the
loop as if it were the last statement in the statement block.
Do-while loop.
do
block instructions
while (Expression);
In this type of loop instruction block is executed once so long less, and that
block of instruction will be executed while expression evaluates to true.
While loop
while (Expression)
block instructions
11. As in do-while loop in the previous section, the statement block is executed
while a condition is met (while expression evaluates to true), but in this
case, the condition is checked before start first run loop, so if expression
evaluates to false in the first iteration, then the statement block will not
execute any time.
Vectors
To handle collections of objects of the same type in a single structured
vectores12 variable is used. In Java, the vectors are actually objects and
therefore it can call its methods (as discussed in the next chapter).
There are two equivalent ways to declare vectors in Java:
1) type nombreDelVector [];
2) type [] nombreDelVector;
Declaration of the superclass (inheritance)
The superclass is the class from which another class inherits all the
attributes and methods. The way to declare that a class inherits from
another is:
class ClassName extends NombreSuperclase
example:
Nif class extends Dni
Declares a class that inherits Nif all attributes and
Dni class methods.
Abstract
Abstract classes can not be instanciadas17. These are for declare
subclasses should override those methods that have been declared
abstract. This does not mean that all methods of an abstract class
abstractos18 should be even possible that none of them is. Even in this
latter case, the class is considered abstract and not be declared Objects
of this class.
When any of the methods of a class is declared abstract class must
abstract necessarily be, otherwise, the compiler generates a message
error.