9月3日 周一

src/Example14.java

@@ -1,2 +1,9 @@
-package PACKAGE_NAME;public class Example14 {
+public class Example14 {
+    public static void main(String[] args) {
+        int sum = 0;
+        for (int i = 1; i <= 4; i++) {
+            sum += i;
+        }
+        System.out.println("sum = " + sum);
+    }
 }

src/Example16.java

@@ -1,2 +1,12 @@
-package PACKAGE_NAME;public class Example16 {
+public class Example16 {
+    public static void main(String[] args) {
+        int x = 1;
+        while (x <= 4) {
+            System.out.println("x = " + x);
+            if (x == 3) {
+                break;
+            }
+            x ++;
+        }
+    }
 }

src/Example17.java

@@ -1,2 +1,12 @@
-package PACKAGE_NAME;public class Example17 {
+public class Example17 {
+    public static void main(String[] args) {
+        int x = 1;
+        while (x <= 4) {
+            System.out.println("x = " + x);
+            if (x == 3) {
+                continue;
+            }
+            x ++;
+        }
+    }
 }

src/SuperMarket.java

@@ -1,2 +1,56 @@
-package PACKAGE_NAME;public class SuperMarket {
+import java.util.Scanner;
+
+public class SuperMarket {
+    /*
+     * 模拟商城购物小系统：
+     * 1.用户选择商品后，后台计算商品价格；
+     * 2.使用while循环实现用户多次购买商品。
+     */
+    public static void main(String[] args) {
+        double cup = 18.8;          //水杯价格
+        double apple = 12.5;        //苹果价格
+        double banana = 15.5;       //香蕉价格
+        int i = 0;                  // 用户购买的商品序列
+
+        String continueShopping = "Y";  // 是否继续购物
+        System.out.println("==============天津现代小卖部================");
+        System.out.println("1.水杯的价格为：" + cup + "元");
+        System.out.println("2.苹果的价格为：" + apple + "元");
+        System.out.println("3.香蕉的价格为：" + banana + "元");
+
+        while (continueShopping.equals("Y")) {
+            Scanner sc1 = new Scanner(System.in);
+            System.out.println("请输入你需要购买商品的序列号：");
+            i = sc1.nextInt();
+
+            switch (i) {
+                case 1:
+                    System.out.println("请输入你需要购买水杯的数量:");
+                    int cupnumber=sc1.nextInt();
+                    double cupnum=cupnumber*cup;
+                    System.out.println("你购买了水杯"+cupnumber+"个，需要花费"+cupnum+"元");
+                    System.out.println("需要继续购买请输入Y，否则输入N");
+                    continueShopping=sc1.next();
+                    break;
+                case 2:
+                    System.out.println("请输入你需要购买苹果的数量:");
+                    int applenumber=sc1.nextInt();
+                    double applenum=applenumber*apple;
+                    System.out.println("你购买了苹果"+applenumber+"斤，需要花费"+applenum+"元");
+                    System.out.println("需要继续购买请输入Y，否则输入N");
+                    continueShopping=sc1.next();
+                    break;
+                case 3:
+                    System.out.println("请输入你需要购买香蕉的数量:");
+                    int banananumber=sc1.nextInt();
+                    double banananum=banananumber*banana;
+                    System.out.println("你购买了香蕉"+banananumber+"斤，需要花费"+banananum+"元");
+                    System.out.println("需要继续购买请输入Y，否则输入N");
+                    continueShopping=sc1.next();
+                    break;
+            }
+        }
+
+        System.out.println("期待您的下次光临！");
+    }
 }