Update: replaced hashCode() with identityHashCode() to understand String Jan 23, 2025 java_super_keyword super keyword use-cases Feb 14, 2025 java_this_keyword this keyword in-depth: constructor chaining, method chaning, object p… Feb 4, 2025 README.md Documentation: Added documentation of re...
File Name Main.java Lines 74 Statements 53 Percent Branch Statements 3.8 Method Call Statements 15 Percent Lines with Comments 5.4 Classes and Interfaces 2 Methods per Class 6.00 Average Statements per Method 2.75 Line Number of Most Complex Method 61 Name of Most Complex Method Student.setAge() ...
import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import java.util.ArrayList; import java.util.List; public class PeopleDAO { public List<Person> getAllPeople() throws SQLException { String SQL = "SELECT * FROM people"; Connec...
The name of the constructor method is the same as the class name. By class name's convention, it begins with an uppercase (instead of lowercase for ordinary methods). Constructor has no return type. It implicitly returns void. No return statement is allowed inside the constructor's body. C...
OOP helps to keep the Java code DRY "Don't Repeat Yourself", and makes the code easier to maintain, modify and debug OOP makes it possible to create full reusable applications with less code and shorter development time Tip:The "Don't Repeat Yourself" (DRY) principle is about reducing the...
public class Student extends Person {private int studentId;public Student(String name, int age, int studentId) {super(name, age); // 调用父类的构造方法this.studentId = studentId;}public void sayHello() {super.sayHello(); // 调用父类的方法System.out.println("I'm a student with ID " ...
这是父类Final修饰方法with public 这是父类Public修饰方法 这是父类Final修饰方法with public 思考一下类与对象的关系 类的本质是针对某一类事物的整体描述或者定义,是抽象的数据类型,不能代表具体的/详细的某一事物。 例如人,学生,车,房子等,这些可以定义为类,可以描述/定义这些事物具备的特点和行为。
2.Objects can interact with each other for computing tasks.对象之间的交互 用开车来类比 step1:declaration 1.Class: when programming in Java, we begin by declaring a program unit (template) called the Car class, just like we begin with engineering draws in the driving example.(声明类) Attribut...
Java OOP Concepts with Examples In this Java OOPs concepts tutorial, we will learn four major object oriented principles– abstraction, encapsulation, inheritance, and polymorphism. They are also known as four pillars of the object oriented programming paradigm. ...
public void goWith(String name){ // 注意:this在方法中,谁调用这个方法this就代表谁! System.out.println( + "正在和" + name +"比赛"); } 6.封装 面向对象的三大特征:封装、继承、多态。 封装的基本思想: 决定属性和行为归属谁的问题 ...