v2

calculator.java

@@ -13,5 +13,36 @@ public class calculator {
         System.out.print("请选择操作符 (+, -, *, /, %):");
         String operation = scanner.next();
 
+        double result;
+        switch (operation) {
+            case "+":
+                result = num1 + num2;
+                break;
+            case "-":
+                result = num1 - num2;
+                break;
+            case "*":
+                result = num1 * num2;
+                break;
+            case "/":
+                if (num2 == 0) {
+                    System.out.println("错误：除数不能为0");
+                    return;
+                }
+                result = num1 / num2;
+                break;
+            case "%":
+                if (num2 == 0) {
+                    System.out.println("错误：除数不能为0");
+                    return;
+                }
+                result = num1 % num2;
+                break;
+            default:
+                System.out.println("无效的操作符");
+                return;
+        }
 
+        System.out.printf("结果是: %.2f\n", result);
+    }
 }