求大牛看看我這個(gè)代碼應(yīng)該怎么填寫(xiě)
package com.hei;
import java.util.*;
public class lianxi {
?public static void main(String[] args) {
??// 提醒用戶(hù)輸入計(jì)算方法
??Scanner input = new Scanner(System.in);
??System.out.println("請(qǐng)輸入第一個(gè)數(shù):");
??double a = input.nextDouble();
??System.out.println("請(qǐng)輸入第二個(gè)數(shù):");
??double b = input.nextDouble();
??while (true) {
???System.out.println("******************");
???System.out.println("1.輸出兩個(gè)數(shù)的和:");
???System.out.println("2.輸出兩個(gè)數(shù)的差:");
???System.out.println("3.輸出兩個(gè)數(shù)的乘積:");
???System.out.println("4.輸出兩個(gè)數(shù)的商:");
???System.out.println("5.重新輸入數(shù)字");
???System.out.println("6.退出.");
???// 定義變量c保存用戶(hù)選擇的計(jì)算方法
? int c = input.nextInt();
???switch (c) {
???case 1:
????double x = a + b;
????System.out.println("兩個(gè)數(shù)的和:" + x);
????break;
???case 2:
????double x1 = a - b;
????System.out.println("兩個(gè)數(shù)的差:" + x1);
????break;
???case 3:
????double x2 = a * b;
????System.out.println("兩個(gè)數(shù)的乘積:" + x2);
????break;
???case 4:
????double x3 = a / b;
????System.out.println("兩個(gè)數(shù)的商:" + x3);
????break;
???case 5:
????
????break;
???case 6:
????break;
???default:
????System.out.println("請(qǐng)確保輸入范圍在1~5之間");
???}
??}
?}
}
我的想法是在switch中的 case 5返回前面再次要用戶(hù)輸入變量a和b,一開(kāi)始我的想法是定義一個(gè)方法但是這樣a和b是局部變量,我在main方法中調(diào)用不到,想問(wèn)下如何實(shí)現(xiàn)case 5可以返回再次輸入變量a和b
2018-05-28
既然你已經(jīng)定義了值為true的循環(huán)，那可以將
System.out.println("請(qǐng)輸入第一個(gè)數(shù):");
??double a = input.nextDouble();
??System.out.println("請(qǐng)輸入第二個(gè)數(shù):");
??double b = input.nextDouble();
放到while循環(huán)里，每次用戶(hù)計(jì)算完畢或者選擇重新輸入后都會(huì)跳轉(zhuǎn)回輸入數(shù)字欄
2019-02-24
public?class?Print{ ????public?static?void?main(String[]?args)?{ ???????Scanner?input=new?Scanner(System.in); ???????for(int?i?=?0;?i?<4?;)?{ ?????????System.out.print("請(qǐng)輸入1或者2："); ?????????int?a=input.nextInt(); ?????????i++; ?????????if?(a>2){ ?????????System.out.println("您的輸入有誤，請(qǐng)重新輸入！"); ?????????}else{ ???????????i++; ?????????}??? ????????} ????} }希望對(duì)你有幫助??！
2018-05-28
import?java.util.Scanner; public?class?Test?{ ????public?static?void?main(String[]?args)?{ ????????math();//抽取方法 ????} ????public?static?void?math(){ ????????//?提醒用戶(hù)輸入計(jì)算方法 ????????Scanner?input?=?new?Scanner(System.in); ????????System.out.println("請(qǐng)輸入第一個(gè)數(shù):"); ????????double?a?=?input.nextDouble(); ????????System.out.println("請(qǐng)輸入第二個(gè)數(shù):"); ????????double?b?=?input.nextDouble(); ????????while?(true)?{ ????????????System.out.println("******************"); ????????????System.out.println("1.輸出兩個(gè)數(shù)的和:"); ????????????System.out.println("2.輸出兩個(gè)數(shù)的差:"); ????????????System.out.println("3.輸出兩個(gè)數(shù)的乘積:"); ????????????System.out.println("4.輸出兩個(gè)數(shù)的商:"); ????????????System.out.println("5.重新輸入數(shù)字"); ????????????System.out.println("6.退出."); ????????????//?定義變量c保存用戶(hù)選擇的計(jì)算方法 ????????????int?c?=?input.nextInt(); ????????????switch?(c)?{ ????????????????case?1: ????????????????????double?x?=?a?+?b; ????????????????????System.out.println("兩個(gè)數(shù)的和:"?+?x); ????????????????????break; ????????????????case?2: ????????????????????double?x1?=?a?-?b; ????????????????????System.out.println("兩個(gè)數(shù)的差:"?+?x1); ????????????????????break; ????????????????case?3: ????????????????????double?x2?=?a?*?b; ????????????????????System.out.println("兩個(gè)數(shù)的乘積:"?+?x2); ????????????????????break; ????????????????case?4: ????????????????????double?x3?=?a?/?b; ????????????????????System.out.println("兩個(gè)數(shù)的商:"?+?x3); ????????????????????break; ????????????????case?5: ????????????????????math();//再次執(zhí)行該方法 ????????????????????break; ????????????????case?6: ????????????????????System.out.println("退出成功"); ????????????????????return;//完全停止 ????????????????default: ????????????????????System.out.println("請(qǐng)確保輸入范圍在1~5之間"); ????????????} ????????} ????} }希望對(duì)你有幫助
2018-05-28
可以把main方法里邊的代碼?抽成一個(gè)方法，然后case5?就調(diào)這個(gè)方法
2018-05-28
你可以直接把整個(gè)main的代碼寫(xiě)到 ?while（）{代碼} ?里去，怎么樣跳出隨你自己寫(xiě)，這里我覺(jué)得你最好寫(xiě)一個(gè)方法，把這些代碼放到方法里去，然后在main里調(diào)用方法，，不過(guò)是不是你還沒(méi)學(xué)到這里，，哈哈