Home Java javaTutorial What does obj mean in java

What does obj mean in java

May 01, 2024 pm 06:18 PM

In Java, "obj" is a variable name that refers to an object, which is an instance of a class and represents an entity in the application. To create an object, define the class, create an instance using the new keyword, and assign its reference to a variable (such as obj). The object can access properties and methods (such as obj.name = "John Doe"), and its life cycle ends from creation to when it is no longer referenced. The garbage collector will automatically release the memory of the object that is no longer referenced.

What does obj mean in java

obj in Java

In Java, "obj" is a variable name, representing an object. An object is an instance of a class that represents an actual entity in the application.

How to create an object

To create an object, you need:

  1. Define a class that describes the properties and behavior of the object.
  2. Use the new keyword to create an instance of a class. This allocates memory and creates a new object of this class.
  3. Assign an object reference to a variable, usually called obj.

For example:

class Person {
    String name;
    int age;
}

Person obj = new Person();
Copy after login

In this example, obj is a reference to a newly created Person Instance of class.

Working with Objects

Once an object is created, it can be used to access its properties and methods. You can use the dot operator (.) to access object properties and call its methods.

For example:

obj.name = "John Doe";
int age = obj.getAge();
Copy after login

The life cycle of an object

The life cycle of an object begins when it is created and ends when it is no longer used. until the program is referenced. The garbage collector automatically releases memory for objects that are no longer referenced.

Note:

  • "obj" is just a variable name, you can freely choose to name the variable.
  • Objects can store any type of data, including other objects.
  • The object reference itself occupies memory space, but it does not occupy the space occupied by the object itself.

The above is the detailed content of What does obj mean in java. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
1 months ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Top 4 JavaScript Frameworks in 2025: React, Angular, Vue, Svelte Top 4 JavaScript Frameworks in 2025: React, Angular, Vue, Svelte Mar 07, 2025 pm 06:09 PM

This article analyzes the top four JavaScript frameworks (React, Angular, Vue, Svelte) in 2025, comparing their performance, scalability, and future prospects. While all remain dominant due to strong communities and ecosystems, their relative popul

How do I implement multi-level caching in Java applications using libraries like Caffeine or Guava Cache? How do I implement multi-level caching in Java applications using libraries like Caffeine or Guava Cache? Mar 17, 2025 pm 05:44 PM

The article discusses implementing multi-level caching in Java using Caffeine and Guava Cache to enhance application performance. It covers setup, integration, and performance benefits, along with configuration and eviction policy management best pra

Spring Boot SnakeYAML 2.0 CVE-2022-1471 Issue Fixed Spring Boot SnakeYAML 2.0 CVE-2022-1471 Issue Fixed Mar 07, 2025 pm 05:52 PM

This article addresses the CVE-2022-1471 vulnerability in SnakeYAML, a critical flaw allowing remote code execution. It details how upgrading Spring Boot applications to SnakeYAML 1.33 or later mitigates this risk, emphasizing that dependency updat

How does Java's classloading mechanism work, including different classloaders and their delegation models? How does Java's classloading mechanism work, including different classloaders and their delegation models? Mar 17, 2025 pm 05:35 PM

Java's classloading involves loading, linking, and initializing classes using a hierarchical system with Bootstrap, Extension, and Application classloaders. The parent delegation model ensures core classes are loaded first, affecting custom class loa

Node.js 20: Key Performance Boosts and New Features Node.js 20: Key Performance Boosts and New Features Mar 07, 2025 pm 06:12 PM

Node.js 20 significantly enhances performance via V8 engine improvements, notably faster garbage collection and I/O. New features include better WebAssembly support and refined debugging tools, boosting developer productivity and application speed.

Iceberg: The Future of Data Lake Tables Iceberg: The Future of Data Lake Tables Mar 07, 2025 pm 06:31 PM

Iceberg, an open table format for large analytical datasets, improves data lake performance and scalability. It addresses limitations of Parquet/ORC through internal metadata management, enabling efficient schema evolution, time travel, concurrent w

How to Share Data Between Steps in Cucumber How to Share Data Between Steps in Cucumber Mar 07, 2025 pm 05:55 PM

This article explores methods for sharing data between Cucumber steps, comparing scenario context, global variables, argument passing, and data structures. It emphasizes best practices for maintainability, including concise context use, descriptive

How can I implement functional programming techniques in Java? How can I implement functional programming techniques in Java? Mar 11, 2025 pm 05:51 PM

This article explores integrating functional programming into Java using lambda expressions, Streams API, method references, and Optional. It highlights benefits like improved code readability and maintainability through conciseness and immutability

See all articles