C+中的循环+；检查错误输入，如果用户输入正确，则重新启动程序 我是C++新手。我已经给了作业，在作业中我必须计算分数并要求用户输入。如果他输入错误，我必须重新启动程序。如果用户输入了正确的输入，我必须处理数据，然后再次询问他是否要检查其他计算。到目前为止，我已经编写了此代码。我不知道如果用户输入错误，如何在程序中再次循环，如果成功，如何重新启动程序。请给我指导一下。谢谢 #include <cstdlib> #include <iostream> using namespace std; int main(int argc, char *argv[]) { //Declaring Variable char choice; char input; //Promptin User to Enter his/her Choice cout<<"Enter C or c for Computer Science: \n" ; cout<<"Enter S or s for Software Engineering: \n"; cout<<"Enter T or T for Telecom Engineering: \n"; cout<<"Select any option from the above Menu: "; cin>>input; if (input != 'c' || input != 'C'){ cout<<"Invalid input! Enter the correct input option again"; }else if (input != 's' || input != 'S' ){ cout<<"Invalid input! Enter the correct input option again"; }else if (input != 't' || input != 'T' ){ cout<<"Invalid input! Enter the correct input option again"; }else if (input == 'a' || input == 'A'){ } system("pause"); return 0; } #包括 #包括 使用名称空间std； int main（int argc，char*argv[]） { //声明变量 字符选择； 字符输入； //提示用户输入他/她的选择 cout
您可以使用一个简单的C+中的循环+；检查错误输入，如果用户输入正确，则重新启动程序 我是C++新手。我已经给了作业，在作业中我必须计算分数并要求用户输入。如果他输入错误，我必须重新启动程序。如果用户输入了正确的输入，我必须处理数据，然后再次询问他是否要检查其他计算。到目前为止，我已经编写了此代码。我不知道如果用户输入错误，如何在程序中再次循环，如果成功，如何重新启动程序。请给我指导一下。谢谢 #include <cstdlib> #include <iostream> using namespace std; int main(int argc, char *argv[]) { //Declaring Variable char choice; char input; //Promptin User to Enter his/her Choice cout<<"Enter C or c for Computer Science: \n" ; cout<<"Enter S or s for Software Engineering: \n"; cout<<"Enter T or T for Telecom Engineering: \n"; cout<<"Select any option from the above Menu: "; cin>>input; if (input != 'c' || input != 'C'){ cout<<"Invalid input! Enter the correct input option again"; }else if (input != 's' || input != 'S' ){ cout<<"Invalid input! Enter the correct input option again"; }else if (input != 't' || input != 'T' ){ cout<<"Invalid input! Enter the correct input option again"; }else if (input == 'a' || input == 'A'){ } system("pause"); return 0; } #包括 #包括 使用名称空间std； int main（int argc，char*argv[]） { //声明变量 字符选择； 字符输入； //提示用户输入他/她的选择 cout,c++,C++,您可以使用一个简单的do while循环： bool valid_input = false; do { // Code to read and validate the input... } while (valid_input == false); 如果输入有效，则将valid\u input设置为true，循环将结束 在一个不相关的注释中，如果您不使用大写或小写，请使用例如，因此您只需比较字母一次。例如std:：tolower（输入） ！=“c”只要答案是用开关语句定义的，这
do whilebool valid_input = false;
do
{
// Code to read and validate the input...
} while (valid_input == false);
valid\u inputtrue在一个不相关的注释中，如果您不使用大写或小写，请使用例如，因此您只需比较字母一次。例如
std:：tolower（输入）
！=“c”ans#包括
#包括
使用名称空间std；
int main（）{
字符输入；
char ans；//正确答案，错误答案
做{
cout用户输入处理非常常见，通常可以使用类似的模式
基本上，您重新请求输入。您处理有效的选择并中断循环，当选择无效时显示错误，让循环再次请求输入
备注1：通过在这里不使用switch case，我可以立即中断循环。我立即中断循环是为了避免两次指定条件或使用标志，这也是我使用无结束条件的循环的原因
备注2:std:：flush
用于在提示行上输入。它确保在等待输入之前显示提示
char inp = 0;
while (true) {
std::cout << "Give input (a, b): " << std::flush;
std::cin >> inp;
inp = std::tolower(inp);
if (inp == 'a') {
std::cout << 'a\n';
break;
}
if (inp == 'b') {
std::cout << 'b\n';
break;
}
std::cout << "invalid choice (" << inp << ")";
}
charinp=0；
while（true）{
std：：cout-inp；
inp=std:：tolower（inp）；
如果（inp='a'）{
STD：谢谢大家支持。实际上这是我的第一个C++程序，抱歉我用过单词指导。实际上我已经成功编译了。请检查我的程序，我知道你不需要，但是我想知道我能不能在里面多加一些。
#include <cstdlib>
#include <iostream>
#include <conio.h>
using namespace std;
int main(int argc, char *argv[])
{
//Declaring Variable
char choice;
char input;
int addTest = 0, matricMarks = 0 , interMarks = 0 , result = 0;
start: //Label
system("cls"); // Clear the Screen
//Prompting User to Enter his/her Choice
cout<<"Please Select the Degree Programme in which you are interested in to take Addmission: ";
cout<<"\nEnter C or c for Computer Science: "<<endl ;
cout<<"Enter S or s for Software Engineering: "<<endl;
cout<<"Enter T or t for Telecom Engineering: \n"<<endl;
cout<<"\nSelect any option from the above Menu: ";
cin>>input;
//Switch Statement Started
switch(input){
//Case C Started
case 'c':
case 'C':
{
cout<<"Enter your Marks in Addmission Test: ";
cin>>addTest;
cout<<"Enter your Marks in Matric Degree: ";
cin>>matricMarks;
cout<<"Enter your Marks in Intermediate Degree: ";
cin>>interMarks;
result = (addTest * 0.20)+(matricMarks * 0.30)+(interMarks * 0.50);
if (result >= 70)
{
cout<<"\nCongratulations! You are eligible for the Computer Science degree program :)"<<endl;
}
else
{
cout<<"Sorry you Do not qualify for Computer Science Degree Programme: "<<endl;
system("pause");
}
break;
}//Case C Closeed
//Case s Started
case 's':
case 'S':
{
cout<<"Enter your Marks in Addmission Test: ";
cin>>addTest;
cout<<"Enter your Marks in Matric Degree: ";
cin>>matricMarks;
cout<<"Enter your Marks in Intermediate Degree: ";
cin>>interMarks;
result = (addTest * 0.20)+(matricMarks * 0.30)+(interMarks * 0.50);
if (result >= 85)
{
cout<<"\nCongratulations! You are eligible for the Software Enginnering degree program :)"<<endl;
}
else
{
cout<<"\nSorry! you Do not Qualify for Software Engineering Degree: "<<endl;
system("pause");
}
break;
}//Case S Closed
//Case t Started
case 't':
case 'T':
{
cout<<"Enter your Marks in Addmission Test: ";
cin>>addTest;
cout<<"Enter your Marks in Matric Degree: ";
cin>>matricMarks;
cout<<"Enter your Marks in Intermediate Degree: ";
cin>>interMarks;
result = (addTest * 0.20)+(matricMarks * 0.30)+(interMarks * 0.50);
if (result >= 80)
{
cout<<"\nCongratulations! You are eligible for the Telecom Engineering degree program :)"<<endl;
}
else
{
cout<<"Sorry you Do not Qualify for Telecom Enginnering Degree Programme: "<<endl;
system("pause");
}
break;
}//Case t Closed
//Default Case Started
default:
{
cout<<"\nInvalid input! Enter the correct option again: \n";
system("pause");
goto start; //Jump To Label Start
}//Deafult Case Closed
}// Switch Statement Close
//do while Loop Started
do{
cout<<"\nDo you want to check your eligibility in some other degree program y/n? : ";
cin>>choice;
if (choice=='Y'||choice=='y')
{
goto start; //jump to Label start:
}
else if (choice=='N'||choice=='n')
{
break;
}
}while(choice == 'y' || choice == 'Y');
//Do while Loop Closed
system("pause");
return 0;
}
#包括
#包括
#包括
使用名称空间std；
int main（int argc，char*argv[]）
{
//声明变量
字符选择；
字符输入；
int addTest=0，矩阵标记=0，中间标记=0，结果=0；
开始：//标签
系统（“cls”）；//清除屏幕
//提示用户输入他/她的选择
使用do while（）
loop？input
必须同时是c
和c
（如何？）而不是满足input！=“c”| input！=“c”
。为什么这么难？@LogicStuff几乎是不合逻辑的，逻辑对某些人来说有多难。：）堆栈溢出不是聊天室“指导”。这是一个问答网站。你的问题是什么？为什么会被否决？这个问题可能是基本的，没有问题形式，但这不是一个坏问题，它很有趣，因为几乎每个开始编程的人都会遇到这个问题。如果有什么问题，它可能会作为一个副本关闭。相关的“列表显示，但我建议使用它，因为它有未定义的行为（未初始化的变量）您可以使用std:：tolower
或每个区块有多个案例：case'S'：\ncase'S'：ans=1；break；
很高兴看到一些反馈。遗憾的是，这还不够。但是，更常见的反馈方式是通过向上或向下投票、接受和评论问题/答案（向上投票也是鼓励人们继续帮助你的一种方式）。对于代码审查，我指示你。请注意，他们也有规则和约定。我确实注意到，尽管所有答案都建议你使用while循环，但你使用了goto。goto可能有用处，在你的练习中，它仍然很简单。然而（结束）使用goto's可能会很快出现问题，我希望你在完成作业的当晚不会遇到困难。它们几乎不再使用，因为3个goto's的组合可能已经很难遵循。在这种情况下，goto start可以由bool restart=true；do{…}代替while（restart）
loop和restart=false；
在choice==“n”
分支中（还请注意，重新启动问题的有效性检查是错误的：使用调试器和一些不同的输入进行检查）
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
char askInputChoice(const std::string& prompt, const std::vector<char>& valid)
{
char inp = 0;
while (true) {
std::cout << prompt << ": " << std::flush;
std::cin >> inp;
inp = std::tolower(inp);
if (std::find(valid.begin(), valid.end(), inp) != valid.end()) {
break;
}
std::cout << "invalid choice (" << inp << ")\n";
}
return inp;
}
int main()
{
char inp = askInputChoice("Give input (a, b)", std::vector<char>{'a','b'});
switch (inp) {
case 'a':
std::cout << "a\n";
break;
case 'b':
std::cout << "b\n";
break;
}
}
#include <cstdlib>
#include <iostream>
#include <conio.h>
using namespace std;
int main(int argc, char *argv[])
{
//Declaring Variable
char choice;
char input;
int addTest = 0, matricMarks = 0 , interMarks = 0 , result = 0;
start: //Label
system("cls"); // Clear the Screen
//Prompting User to Enter his/her Choice
cout<<"Please Select the Degree Programme in which you are interested in to take Addmission: ";
cout<<"\nEnter C or c for Computer Science: "<<endl ;
cout<<"Enter S or s for Software Engineering: "<<endl;
cout<<"Enter T or t for Telecom Engineering: \n"<<endl;
cout<<"\nSelect any option from the above Menu: ";
cin>>input;
//Switch Statement Started
switch(input){
//Case C Started
case 'c':
case 'C':
{
cout<<"Enter your Marks in Addmission Test: ";
cin>>addTest;
cout<<"Enter your Marks in Matric Degree: ";
cin>>matricMarks;
cout<<"Enter your Marks in Intermediate Degree: ";
cin>>interMarks;
result = (addTest * 0.20)+(matricMarks * 0.30)+(interMarks * 0.50);
if (result >= 70)
{
cout<<"\nCongratulations! You are eligible for the Computer Science degree program :)"<<endl;
}
else
{
cout<<"Sorry you Do not qualify for Computer Science Degree Programme: "<<endl;
system("pause");
}
break;
}//Case C Closeed
//Case s Started
case 's':
case 'S':
{
cout<<"Enter your Marks in Addmission Test: ";
cin>>addTest;
cout<<"Enter your Marks in Matric Degree: ";
cin>>matricMarks;
cout<<"Enter your Marks in Intermediate Degree: ";
cin>>interMarks;
result = (addTest * 0.20)+(matricMarks * 0.30)+(interMarks * 0.50);
if (result >= 85)
{
cout<<"\nCongratulations! You are eligible for the Software Enginnering degree program :)"<<endl;
}
else
{
cout<<"\nSorry! you Do not Qualify for Software Engineering Degree: "<<endl;
system("pause");
}
break;
}//Case S Closed
//Case t Started
case 't':
case 'T':
{
cout<<"Enter your Marks in Addmission Test: ";
cin>>addTest;
cout<<"Enter your Marks in Matric Degree: ";
cin>>matricMarks;
cout<<"Enter your Marks in Intermediate Degree: ";
cin>>interMarks;
result = (addTest * 0.20)+(matricMarks * 0.30)+(interMarks * 0.50);
if (result >= 80)
{
cout<<"\nCongratulations! You are eligible for the Telecom Engineering degree program :)"<<endl;
}
else
{
cout<<"Sorry you Do not Qualify for Telecom Enginnering Degree Programme: "<<endl;
system("pause");
}
break;
}//Case t Closed
//Default Case Started
default:
{
cout<<"\nInvalid input! Enter the correct option again: \n";
system("pause");
goto start; //Jump To Label Start
}//Deafult Case Closed
}// Switch Statement Close
//do while Loop Started
do{
cout<<"\nDo you want to check your eligibility in some other degree program y/n? : ";
cin>>choice;
if (choice=='Y'||choice=='y')
{
goto start; //jump to Label start:
}
else if (choice=='N'||choice=='n')
{
break;
}
}while(choice == 'y' || choice == 'Y');
//Do while Loop Closed
system("pause");
return 0;
}