Interpretation of Java documentation: Usage analysis of hasNextInt() method of Scanner class

Java Document Interpretation: Usage analysis of the hasNextInt() method of the Scanner class, specific code examples are required

Introduction
The Scanner class in Java is a practical tool. Can be used to scan and parse text from an input stream. The Scanner class provides a variety of methods to meet different needs, one of which is the hasNextInt() method. This method is used to check whether the next input is of type int.

Method syntax
The syntax of the hasNextInt() method is as follows:
public boolean hasNextInt()

Method return value
hasNextInt() method returns a boolean value, if If an input is of type int, it returns true; otherwise it returns false.

Usage example

The following is a specific code example that demonstrates the use of the hasNextInt() method:

import java.util.Scanner;

public class Example {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        System.out.print("请输入一个整数：");
        if (scanner.hasNextInt()) {
            int num = scanner.nextInt();
            System.out.println("您输入的整数为：" + num);
        } else {
            System.out.println("输入的不是整数");
        }

        scanner.close();
    }
}

Code analysis

1. First , we imported the java.util.Scanner class in order to use the functions of the Scanner class.
2. In the main method, a Scanner object is created and the input stream System.in is passed to the Scanner constructor as a parameter. This way we can read input from the console.
3. Use the System.out.print method to output prompt information and prompt the user to enter an integer.
4. Call the hasNextInt() method to check whether the next input is of type int. If the return value is true, continue executing the following code; if it is false, output "The input is not an integer".
5. If the input is indeed of type int, we can get the integer by calling the nextInt() method and assign it to the variable num.
6. Finally, we use the System.out.println method to output "The integer you entered is:" plus the integer entered by the user.
7. Finally, call the scanner.close() method to close the Scanner object and release resources.

Summary
By using the hasNextInt() method, we can easily determine whether the input is of type int. This method can be very useful when processing user input and avoid runtime exceptions.

However, it should be noted that if the input is not of type int, calling the nextInt() method will throw an InputMismatchException. Therefore, when using the hasNextInt() method, we should first call the hasNextInt() method to determine whether it is an int type, and then call the nextInt() method to obtain the integer value.

I hope that through this specific code example, you will have a clearer understanding of the hasNextInt() method of the Scanner class and be able to apply it correctly in actual development.

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