我不断收到 "Scanner cannot be resolved to a type" 错误。我正在使用 Java 和 Visual Studio，这是给初学者的 Java class

Question

这是给初学者的 java class。我不断收到“扫描仪无法解析为类型”错误。我正在使用 Visual Studio 和 JDK 16.0.2 我也刚刚在这台笔记本电脑上安装了 Visual Studio 和 Java。我正在为我的 class 编写这个抵押贷款计算器程序，它在我添加 while 循环以捕获用户输入错误之前工作。现在它给了我以前没有的“扫描仪”错误。我添加并移动了几行代码，突然间它给了我这个“扫描仪”错误。以下是完整代码：

  package com.phillip;
  import java.text.NumberFormat;
  import java.util.Scanner;

  public class Main{

        public static void main(String[] args) {
              final byte MONTHS_IN_YEAR = 12;
              final byte PERCENT = 100;

              int principal = 0;
              float monthlyInterest = 0;
              int numberOfPayments = 0;

              Scanner scanner = new Scannner(System.in);

              while (true) {
                    System.out.println("Principal: ");
                    principal = scanner.nextInt();
                    if (principal >= 1000 && principal <= 1_000_000) {
                          break;
                    }
                    System.out.println("Enter a value between 1000 and 1000000");
              }

              while (true) {
                    System.out.println("Annual Interest Rate: ");
                    float annualInterest = scanner.nextFloat();
                    if (annualInterest >= 1 && annualInterest <= 30) {
                          monthlyInterest = annualInterest / PERCENT / MONTHS_IN_YEAR;
                          break;
                    }
                    System.out.println("Enter a value between 1 and 30");
              }

              while (true) {
                    System.out.println("Period (Years): ");
                    byte years = scanner.nextByte();
                    if (years >= 1 && years <= 30) {
                          numberOfPayments = years * MONTHS_IN_YEAR;
                          break;
                    }
                    System.out.println("Enter a value between 1 & 30");
              }

              double mortgage = principal 
                    * (monthlyInterest * Math.pow(1 + monthlyInterest, numberOfPayments)) 
                    / (Math.pow(1 + monthlyInterest, numberOfPayments) - 1);

              String mortgageFormatted = NumberFormat.getCurrencyInstance().format(mortgage);
              System.out.println("Mortgage: " + mortgageFormatted);
        }
  }

Answer 1

我相信你打错了

Scanner scanner = new Scannner(System.in);

'Scannner' 而不是 'Scanner'

我不断收到 "Scanner cannot be resolved to a type" 错误。我正在使用 Java 和 Visual Studio，这是给初学者的 Java class

I keep getting an "Scanner cannot be resolved to a type" error. I am using Java and Visual Studio and this is for a beginner Java class

java

visual-studio

java.util.scanner