我是C ++的初学者,试图创建一个简单的控制台程序来计算线性方程的'm'和'b'...来解析用户提供的输入双,我正在使用字符串流和使用try-catch块检查错误输入。即使catch块有一个全局异常,持久性错误也会继续跟踪[方程Solver.exe中的0x74c8b9bc处的未处理异常:Microsoft C ++异常:[rethrow]在内存位置0x00000000 ..]
double XOne;`enter code here`
double YOne;
double XTwo;
double YTwo;
bool inputCheck = false;
while (inputCheck == false)
{
Clear();
WriteLine("**Linear Equation**");
Write("X1: ");
string xone = ReadLine();
Write("Y1: ");
string yone = ReadLine();
Write("X2: ");
string xtwo = ReadLine();
Write("Y2: ");
string ytwo = ReadLine();
try
{
stringstream s1(xone);
if (s1 >> XOne) { s1 >> XOne; } else { throw; }
stringstream s2(yone); // consider I give an invalid input for this variable
if (s2 >> YOne) { s2 >> YOne; } else { throw; } // this doesn't solve the problem
stringstream s3(xtwo);
if (s3 >> XTwo) { s3 >> XTwo; } else { throw; }
stringstream s4(ytwo);
if (s4 >> YTwo) { s4 >> YTwo; } else { throw; }
}
catch (...) { WriteLine("Invalid Input"); ReadLine(); }
}
LinearEquation equation;
equation.Initialize(XOne, YOne, XTwo, YTwo);
stringstream s5;
s5 << equation.m;
string m = s5.str();
stringstream s6;
s6 << equation.b;
string b = s6.str();
Write("Y = ");
Write(m);
Write("X + ");
WriteLine(b);
ReadLine();
修改 第一个建议像魅力一样......谢谢! 这是我根据评论者修改后的代码。
double XOne;
double YOne;
double XTwo;
double YTwo;
bool inputCheck = false;
while (inputCheck == false)
{
Clear();
WriteLine("**Linear Equation**");
Write("X1: ");
string xone = ReadLine();
Write("Y1: ");
string yone = ReadLine();
Write("X2: ");
string xtwo = ReadLine();
Write("Y2: ");
string ytwo = ReadLine();
try
{
stringstream s1(xone);
if (s1 >> XOne) { s1 >> XOne; } else { throw runtime_error("Invalid Input"); }
stringstream s2(yone);
if (s2 >> YOne) { s2 >> YOne; } else { throw runtime_error("Invalid Input"); }
stringstream s3(xtwo);
if (s3 >> XTwo) { s3 >> XTwo; } else { throw runtime_error("Invalid Input"); }
stringstream s4(ytwo);
if (s4 >> YTwo) { s4 >> YTwo; } else { throw runtime_error("Invalid Input"); }
}
catch (runtime_error e) { WriteLine(e.what()); ReadLine(); }
}
LinearEquation equation;
equation.Initialize(XOne, YOne, XTwo, YTwo);
stringstream s5;
s5 << equation.m;
string m = s5.str();
stringstream s6;
s6 << equation.b;
string b = s6.str();
Write("Y = ");
Write(m);
Write("X + ");
WriteLine(b);
ReadLine();
答案 0 :(得分:14)
throw
只能在处理异常时使用(即在catch块或直接或间接从catch块调用的函数),否则你必须使用带参数的throw这通常是某种异常对象。
如果在未处理异常时执行throw
,则会调用std::terminate
来结束您的程序。
e.g。 (在#include <stdexcept>
之后)
throw std::runtime_error("Bad input");