Java计算器，实现了加减乘除

import java.text.DecimalFormat; import java.util.Scanner; public class App { public static void main(String[] args) { Scanner scanner = new Scanner(System.in); DecimalFormat df = new DecimalFormat("0.##"); String continueCalculation = "Y"; // 循环让用户进行计算 while ("Y".equalsIgnoreCase(continueCalculation)) { System.out.println("请输入要执行的操作（加法、减法、乘法、除法）："); String operation = scanner.nextLine(); System.out.println("请输入第一个数字："); double num1 = scanner.nextDouble(); System.out.println("请输入第二个数字："); double num2 = scanner.nextDouble(); scanner.nextLine(); // 根据操作类型进行计算 switch (operation) { case "加法": System.out.println("结果是：" + df.format(add(num1, num2))); break; case "减法": System.out.println("结果是：" + df.format(subtract(num1, num2))); break; case "乘法": System.out.println("结果是：" + df.format(multiply(num1, num2))); break; case "除法": if (num2 != 0) { System.out.println("结果是：" + df.format(divide(num1, num2))); } else { System.out.println("除数不能为0"); } break; default: System.out.println("未知的操作"); } // 询问用户是否继续计算 System.out.println("是否继续计算？(Y/N)"); continueCalculation = scanner.nextLine(); } scanner.close(); } public static double add(double num1, double num2) { return num1 + num2; } public static double subtract(double num1, double num2) { return num1 - num2; } public static double multiply(double num1, double num2) { return num1 * num2; } public static double divide(double num1, double num2) { return num1 / num2; } }