What does void mean in java?
In Java, void represents "empty", that is, "returns nothing". When the method is declared, it means that the method has no return value. Void corresponds to a Void class. The Void class is modified with final and is a placeholder class that cannot be instantiated.
#Before, when I was learning the data types of C, I found that there are four data types in C, and there is actually an empty type in it. There is a saying in it: "There is a A class function does not need to return a function value to the caller after being called. This kind of function can be defined as an "empty type". Its type specifier is void. My first reaction at the time was "Since void is a type in C Empty type, so what is void in java?"
void is a keyword in java, which means returning nothing. We often use it in the development process, If a method does not need to return a value, you can use the void keyword, which is also the void keyword in the main method.
public static void getName() {
String name = "username";
System.out.println(name);
}
//main方法
public static void main(String[] args) {
}First of all, we know that Java is a strongly typed language. From the method declaration syntax, we can see that each method must have a return value. The return value type of the method needs to be determined. When defining a method When using void modification, nothing is returned. It can be seen that void should also be regarded as a data type;
And we know that the commonly used data types in Java include 8 basic data types, reference types, etc. .
So what type should the void modifier correspond to?
In fact, void corresponds to a Void class:
The Void class is modified with final, indicating that it cannot be extended. In addition, the constructor is private and cannot be instantiated. ;
The Void class is a non-instantiable placeholder class used to save a reference to a Class object that represents the Java keyword void.
The above is the detailed content of What does void mean in java?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
Java Spring Interview Questions
Aug 30, 2024 pm 04:29 PM
In this article, we have kept the most asked Java Spring Interview Questions with their detailed answers. So that you can crack the interview.
Break or return from Java 8 stream forEach?
Feb 07, 2025 pm 12:09 PM
Java 8 introduces the Stream API, providing a powerful and expressive way to process data collections. However, a common question when using Stream is: How to break or return from a forEach operation? Traditional loops allow for early interruption or return, but Stream's forEach method does not directly support this method. This article will explain the reasons and explore alternative methods for implementing premature termination in Stream processing systems. Further reading: Java Stream API improvements Understand Stream forEach The forEach method is a terminal operation that performs one operation on each element in the Stream. Its design intention is
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
TimeStamp to Date in Java
Aug 30, 2024 pm 04:28 PM
Guide to TimeStamp to Date in Java. Here we also discuss the introduction and how to convert timestamp to date in java along with examples.
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
Java Program to Find the Volume of Capsule
Feb 07, 2025 am 11:37 AM
Capsules are three-dimensional geometric figures, composed of a cylinder and a hemisphere at both ends. The volume of the capsule can be calculated by adding the volume of the cylinder and the volume of the hemisphere at both ends. This tutorial will discuss how to calculate the volume of a given capsule in Java using different methods. Capsule volume formula The formula for capsule volume is as follows: Capsule volume = Cylindrical volume Volume Two hemisphere volume in, r: The radius of the hemisphere. h: The height of the cylinder (excluding the hemisphere). Example 1 enter Radius = 5 units Height = 10 units Output Volume = 1570.8 cubic units explain Calculate volume using formula: Volume = π × r2 × h (4
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
Create the Future: Java Programming for Absolute Beginners
Oct 13, 2024 pm 01:32 PM
Java is a popular programming language that can be learned by both beginners and experienced developers. This tutorial starts with basic concepts and progresses through advanced topics. After installing the Java Development Kit, you can practice programming by creating a simple "Hello, World!" program. After you understand the code, use the command prompt to compile and run the program, and "Hello, World!" will be output on the console. Learning Java starts your programming journey, and as your mastery deepens, you can create more complex applications.
