“商苑面馆 :Java知识串讲”的版本间的差异
来自CloudWiki
(创建页面,内容为“ == 任务二 JAVA程序开发基础 == ===2.1变量和表达式=== *Java练习:面馆点餐 ===2.2智能决策:选择结构=== *三目运算符: <nowi…”) |
|||
第6行: | 第6行: | ||
===2.2智能决策:选择结构=== | ===2.2智能决策:选择结构=== | ||
− | + | ====三目运算符==== | |
<nowiki>package demo1; | <nowiki>package demo1; | ||
第26行: | 第26行: | ||
}</nowiki> | }</nowiki> | ||
− | + | ====if条件语句==== | |
第一种形式: | 第一种形式: | ||
第109行: | 第109行: | ||
− | + | ====if语句的嵌套==== | |
<nowiki>询问顾客吃什么面,并询问其是否加蛋、加油渣 ?将结果反馈给后台。</nowiki> | <nowiki>询问顾客吃什么面,并询问其是否加蛋、加油渣 ?将结果反馈给后台。</nowiki> | ||
− | + | ====if语句的多条件==== | |
<nowiki>import java.util.Scanner; | <nowiki>import java.util.Scanner; | ||
第138行: | 第138行: | ||
}</nowiki> | }</nowiki> | ||
− | + | ====switch语句==== | |
<nowiki>package test; | <nowiki>package test; | ||
第173行: | 第173行: | ||
} | } | ||
+ | } | ||
+ | |||
+ | }</nowiki> | ||
+ | |||
+ | ===2.3重复迭代:循环结构=== | ||
+ | ====while循环==== | ||
+ | <nowiki>package test; | ||
+ | import java.util.Scanner; | ||
+ | public class a7 { | ||
+ | |||
+ | public static void main(String[] args) { | ||
+ | // TODO 自动生成的方法存根 | ||
+ | Scanner sc = new Scanner (System.in); | ||
+ | while (true){ | ||
+ | System.out.println("客观,请问您需要什么面:"); | ||
+ | System.out.print("1.刀削面\n2.蛋黄面\n3.玉米面\n4.牛筋面\n5.幸福小丸仔面\n"); | ||
+ | int m = sc.nextInt(); | ||
+ | switch (m){ | ||
+ | case 1: | ||
+ | System.out.println("您选择的是刀削面"); | ||
+ | break; | ||
+ | case 2: | ||
+ | System.out.println("您选择的是蛋黄面"); | ||
+ | break; | ||
+ | case 3: | ||
+ | System.out.println("您选择的是玉米面"); | ||
+ | break; | ||
+ | case 4: | ||
+ | System.out.println("您选择的是牛筋面"); | ||
+ | break; | ||
+ | case 5: | ||
+ | System.out.println("您选择的是幸福小丸仔面"); | ||
+ | break; | ||
+ | default: | ||
+ | System.out.println("对不起 输入错误"); | ||
+ | break; | ||
+ | } | ||
+ | } | ||
+ | |||
+ | } | ||
+ | |||
+ | }</nowiki> | ||
+ | |||
+ | ====for循环==== | ||
+ | <nowiki>public class test02 { | ||
+ | |||
+ | public static void main(String[] args) { | ||
+ | // TODO Auto-generated method stub | ||
+ | //String a ="hello"; | ||
+ | String [] menu = {"阳春面","油泼面","鸡汤面","火鸡面","安徽板面"}; | ||
+ | for(int i=0;i <5;i++){ | ||
+ | System.out.println(menu[i]); | ||
+ | } | ||
+ | |||
+ | } | ||
+ | |||
+ | }</nowiki> | ||
+ | |||
+ | ====循环的嵌套==== | ||
+ | <nowiki>public class test03 { | ||
+ | |||
+ | public static void main(String[] args) { | ||
+ | // TODO Auto-generated method stub | ||
+ | String [] menu = {"阳春面","油泼面","鸡汤面","火鸡面","安徽板面"}; | ||
+ | String [] drink = {"可乐","啤酒","雪碧"}; | ||
+ | for(int i=0;i<5;i++){ | ||
+ | for(int j=0;j<3;j++){ | ||
+ | System.out.println(menu[i]+"+"+drink[j]); | ||
+ | } | ||
+ | } | ||
} | } | ||
}</nowiki> | }</nowiki> |
2019年3月16日 (六) 08:04的版本
目录
任务二 JAVA程序开发基础
2.1变量和表达式
2.2智能决策:选择结构
三目运算符
package demo1; import java.util.Scanner; public class happy08 { public static void main(String[] args) { // TODO Auto-generated method stub //int a = 10 ;int b = 20; //System.out.println(a==b); Scanner sc = new Scanner(System.in); System.out.println("客官,您是堂吃还是外卖?1.堂吃; 2.外卖"); String s = sc.next(); String s2 = (s.equals("1")) ? "堂吃一位" : "外送一位"; System.out.println(s2); } }
if条件语句
第一种形式:
public class Hello123 { public static void main(String[] args) { // TODO Auto-generated method stub // TODO Auto-generated method stub float mian = 10.0f;//面的价格 float suan = 2.0f;//酸梅汤 float total_pay =0f;//总钱数 Scanner sc = new Scanner(System.in); //问用户要几碗面? System.out.println("请问您要几碗面?"); int num = sc.nextInt(); total_pay = num * mian; //问顾客需不需要饮料(饮料2元一杯) System.out.println("请问您是否需要饮料?Y/n"); String s = sc.next( ); if( s.equals("y")){ total_pay = total_pay + num * suan; } System.out.printf("您一共消费了%f元",total_pay); sc.close(); } }
第2种形式:
package demo1; import java.util.Scanner; public class Tangchi { public static void main(String[] args) { // TODO Auto-generated method stub Scanner sc = new Scanner(System.in); System.out.println("客官,请问您是堂吃还是外送?" +"1.堂吃/2.外送"); String s = sc.next(); if(s.equals("1")){ System.out.println("堂吃一位!"); }else{ System.out.println("外送一位!"); } } }
第3种形式:
package demo1; import java.util.Scanner; public class MianType { public static void main(String[] args) { // TODO Auto-generated method stub Scanner sc = new Scanner(System.in); System.out.println("客官,您几位?"); int num = sc.nextInt(); System.out.println("请问你们吃什么面?"); System.out.println("a.老北京炸酱面;b.刀削面" +"c.油泼面"); String s = sc.next(); if(s.equals("a")){ System.out.printf("老北京炸酱面%d碗",num); }else if(s.equals("b")){ System.out.printf("刀削面%d碗",num); }else if(s.equals("c")){ System.out.printf("油泼面%d碗",num); }else{ System.out.println("不好意思,您需求的面我们这里没有"); } } }
if语句的嵌套
询问顾客吃什么面,并询问其是否加蛋、加油渣 ?将结果反馈给后台。
if语句的多条件
import java.util.Scanner; public class happy09 { public static void main(String[] args) { // TODO Auto-generated method stub float price ;boolean fenqi;boolean firstpay; System.out.println("老板,请问手机多少钱?"); Scanner sc = new Scanner(System.in); price = sc.nextFloat(); System.out.println("老板,请问支不支持分期?"); fenqi = sc.nextBoolean(); System.out.println("老板,请问支不支持零首付?"); firstpay = sc.nextBoolean(); if(price <=1000 && fenqi == true && firstpay == true) { System.out.println("小Case!"); }else { System.out.println("太贵了,买不起~"); } } }
switch语句
package test; import java.util.Scanner; public class a7 { public static void main(String[] args) { // TODO 自动生成的方法存根 Scanner sc = new Scanner (System.in); while (true){ System.out.println("客观,请问您需要什么面:"); System.out.print("1.刀削面\n2.蛋黄面\n3.玉米面\n4.牛筋面\n5.幸福小丸仔面\n"); int m = sc.nextInt(); switch (m){ case 1: System.out.println("您选择的是刀削面"); break; case 2: System.out.println("您选择的是蛋黄面"); break; case 3: System.out.println("您选择的是玉米面"); break; case 4: System.out.println("您选择的是牛筋面"); break; case 5: System.out.println("您选择的是幸福小丸仔面"); break; default: System.out.println("对不起 输入错误"); break; } } } }
2.3重复迭代:循环结构
while循环
package test; import java.util.Scanner; public class a7 { public static void main(String[] args) { // TODO 自动生成的方法存根 Scanner sc = new Scanner (System.in); while (true){ System.out.println("客观,请问您需要什么面:"); System.out.print("1.刀削面\n2.蛋黄面\n3.玉米面\n4.牛筋面\n5.幸福小丸仔面\n"); int m = sc.nextInt(); switch (m){ case 1: System.out.println("您选择的是刀削面"); break; case 2: System.out.println("您选择的是蛋黄面"); break; case 3: System.out.println("您选择的是玉米面"); break; case 4: System.out.println("您选择的是牛筋面"); break; case 5: System.out.println("您选择的是幸福小丸仔面"); break; default: System.out.println("对不起 输入错误"); break; } } } }
for循环
public class test02 { public static void main(String[] args) { // TODO Auto-generated method stub //String a ="hello"; String [] menu = {"阳春面","油泼面","鸡汤面","火鸡面","安徽板面"}; for(int i=0;i <5;i++){ System.out.println(menu[i]); } } }
循环的嵌套
public class test03 { public static void main(String[] args) { // TODO Auto-generated method stub String [] menu = {"阳春面","油泼面","鸡汤面","火鸡面","安徽板面"}; String [] drink = {"可乐","啤酒","雪碧"}; for(int i=0;i<5;i++){ for(int j=0;j<3;j++){ System.out.println(menu[i]+"+"+drink[j]); } } } }