Quickly master Java installation steps and coding methods

Java installation tutorial: quickly master the installation steps and start writing code. Specific code examples are required

1. Background introduction
Java is a widely used computer Programming language that is widely used to develop various types of applications, websites, and enterprise software. In order to successfully use Java for programming development, you first need to correctly install the Java development environment (JDK). This article will introduce the installation steps of Java and provide some specific code examples to help readers quickly get started with basic Java programming.

2. Java installation steps

1. Download JDK
   First, visit the Oracle official website (https://www.oracle.com/java/technologies/javase-jdk11-downloads .html), select the appropriate Java Development Kit version to download. Select the corresponding version of the JDK installation package according to your operating system.
2. Install JDK
   After the download is completed, double-click the installation package to install. During the installation process, you need to follow the default settings step by step until the installation is completed.
3. Configure environment variables
   After the installation is completed, you need to add the JDK installation path to the system environment variables. The specific operations are as follows:
   a. Open the "Computer" or "My Computer" properties and click "Advanced System Settings".
   b. In the "System Properties" window, click the "Environment Variables" button.
   c. In the "System Variables" area, find the variable named "Path" and double-click to edit it.
   d. Add ";C:Program FilesJavajdk-14.0.1 in" at the end of the variable value (this path is the JDK installation path, please modify it according to the actual situation).
   e. Click the "OK" button to save the settings.
4. Verify installation results
   Open the command prompt (or terminal) and enter the command "java -version". If the Java version information can be displayed correctly, the installation is successful.

3. Start writing code
After installing the Java development environment, you can use Java to write your own code. Next, we provide some specific code examples to help readers get started quickly.

1. Hello World
   The following is a simple Java program for outputting "Hello World!" information on the console.

   public class HelloWorld {
       public static void main(String[] args) {
           System.out.println("Hello World!");
       }
   }

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   In Java, every program must contain a class, and the class must contain a main method as the entry point of the program. System.out.println() Used to output information on the console.

2. Calculator
   The following is a simple Java program to implement the function of adding two integers.

   import java.util.Scanner;
   
   public class Calculator {
       public static void main(String[] args) {
           Scanner scanner = new Scanner(System.in);
           System.out.print("请输入第一个数字：");
           int num1 = scanner.nextInt();
           System.out.print("请输入第二个数字：");
           int num2 = scanner.nextInt();
           int sum = num1 + num2;
           System.out.println("两个数字的和为：" + sum);
       }
   }

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   In the above program, we used the import java.util.Scanner; statement to import the Scanner class, which is used to read integers from user input. nextInt() method is used to read integers, nextDouble() is used to read floating point numbers.

4. Summary
Through the introduction of this article, readers can understand the installation steps of Java and have some basic Java programming capabilities. I hope this article can help readers quickly get started with Java programming and achieve further learning and development in the Java field.

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