• Barajar
    Activar
    Desactivar
  • Alphabetizar
    Activar
    Desactivar
  • Frente Primero
    Activar
    Desactivar
  • Ambos lados
    Activar
    Desactivar
  • Leer
    Activar
    Desactivar
Leyendo...
Frente

Cómo estudiar sus tarjetas

Teclas de Derecha/Izquierda: Navegar entre tarjetas.tecla derechatecla izquierda

Teclas Arriba/Abajo: Colvea la carta entre frente y dorso.tecla abajotecla arriba

Tecla H: Muestra pista (3er lado).tecla h

Tecla N: Lea el texto en voz.tecla n

image

Boton play

image

Boton play

image

Progreso

1/32

Click para voltear

32 Cartas en este set

  • Frente
  • Atrás
Thread
A thread is a lightweight sub-process, the smallest unit of processing. It is a separate path to execution that shares common memory space with other threads and is managed by the operating system. It allows a program to run multiple tasks concurrently in a single process.
Array
An array is a data structure that stores a collection of elements of the same type.
Each element in an array can be accessed by its index, which is an integer value starting at 0.
Arrays in Java are fixed in size, meaning that the number of elements they can hold is determined at the time of their creation.
Arrays can be initialised with values when they are created or they can be populated later using loops or other methods.
What is a String?
A String is a sequence of characters in Java, represented by the “String” class. Strings are immutable, which means their value cannot be changed after they are created.
String.length( )
Returns the length of the string
String.charAt(int index)
Returns the character at the specified index (Starts at 0)
String.substring(int beginIndex, int endIndex)
Returns a new string that is a substring of the original string, starting from the beginIndex (inclusive) to the endIndex (exclusive)
String.indexOf(char ch)
Returns the index of the first occurrence of the specified character in the string, or -1 if it is not found.
String.equals(String anotherString)
Compares this string to another string and returns true if they are equal, false otherwise.
What are the data types in Java?
Java has two categories of data types.
Primitives data types - byte, short, int, long, float, double, boolean and char.

Reference/Object data types - String, Arrays, Classes and Interfaces.
What are primitive data types in Java?
They are the basic data types provided by the Java programming language and are used to define the type of a variable.

Byte, short, int, long, float, double, boolean and char.
What are reference/object data types in Java?
These data types are non.primitive, as they are not defined by the language itself, but by the programmer. They hold the memory address of the object they refer to.
What is the difference between a primitive and a reference data type in java?
The main difference is that primitive data types store the actual value, while reference data types store a reference (or pointer) to the memory location where the value is stored.

Primitive data types are passed by value, whereas reference data types are passed by reference.
What is autoboxing in Java?
Autoboxing is the automatic conversion of primitive data types into their corresponding wrapper class object, like int to Integer. This allows primitives to be used in places where objects are required, such as in collections or as method parameters.
What is casting in Java?
Casting refers to the process of converting a value of one data type to another data type.

Implicit casting - widening - is the process of converting a value of a smaller data type to a larger data type.

Explicit casting - narrowing - is the process of converting a value of a larger data type to a smaller data type.
What is a class in Java?
A class is a blueprint of template for creating objects in Java. It defines the properties and behaviour of the objects that can be created from it.
What is an object in Java?
An object is an instance of a class. It is created using the “new” keyword and has its own set of properties and behaviours based on the class it was instantiated from.
What is encapsulation in Java?
Encapsulation is the concept of hiding the internal workings of a class from the outside world. It is achieved by making the class’s data private and providing public methods to access and modify it.
What is inheritance in Java?
Inheritance is the concept of creating a new class from an existing one. The new class (subclass9 inherits the properties and behaviours of the existing one (superclass) and can add its own as well.
What is polymorphism in Java?
Polymorphism is the concept of using a single interface or class to represent multiple types. It allows different objects to be treated as if they were of the same type, based on their common characteristics. It allows objects of different classes to be treated as if they are objects of the same superclass.
What is method overloading in Java?
Method overloading is the ability to create multiple methods with the same name in a class. The methods must have different parameters (number or types) to differentiate between them.
What is method overriding in Java?
Method overriding is the ability of a subclass to provide its own implementation for a method that is already defined in its superclass. The method must have the same name and the same parameters as in the parent class.
What is dynamic polymorphism in Java?
Dynamic polymorphism in Java is the ability of an object to decide which method to call at runtime, based on the type of object that it refers to. This is achieved through method overriding and the use of the “super” keyword.
What is the java class for representing time?
The Java class for representing time is java.time.LocalDateTime
How do you get the current date and time in Java?
You can get the current date and time in Java using the .now() method on the LocalDateTime class.
How do you format a date and time in Java?
You can format a date and time in Java using the .format() method of the DateTimeFormatter class.
What is the difference between the .parse() and .format() methods in Java?
The .parse() method is used to convert a string into a date or time object, while the .format() method is used to convert a date or time into a string.
What is the syntax for accessing an element in an array in Java?
arrayName[index], where index is the position of the element in the array (starting from 0)
What is the syntax for modifying an element in an array in Java?
arrayName[index] = value, where value is the new value of the element. It has to be of the same variable type in order to work
What is the syntax for iterating over an array in Java? And to sort it?
To iterate over an array:
for(type variable : arrayName){
code to execute;
}

To sort an array:
Arrays.sort(arrayName);
What is a Stream in Java?
A Stream is a sequence of objects that can be processed in parallel or sequentially. It provides a way to efficiently process large amounts of data in a declarative way.
What is the purpose of Stream.collect() method?
The Stream.collect() method combines the elements of a stream into a new collection or reduces it to a single value, such as an array or a list.
What is the difference between filter() and map() methods in Stream?
The filter() method is used to select elements as per the Predicate passed as an argument. It returns a Stream of all elements that match the Predicate.

The map() method is used to transform each element of the Stream into a new form by applying a Function on each element. It returns a Stream consisting of the transformed elements.