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我是 C++ 的初学者，并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”...解析用户提供的输入双精度，我正在使用 stringstream 并使用 try -catch 块以检查错误输入。即使 catch 块具有全局异常 [未处理的异常在 Equation Solver.exe 中的 0x74c8b9bc：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();

编辑 第一个建议就像一个魅力......谢谢！这是我根据审稿人修改后的代码。

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();
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1 回答 1

14

throw没有参数只能在处理异常时使用（即在catch块中或从catch块直接或间接调用的函数中），否则您必须使用带有参数的throw，该参数通常是某些异常对象种类。

如果throw在未处理异常时执行，std::terminate将调用以结束您的程序。

例如（之后#include <stdexcept>）

throw std::runtime_error("Bad input");
于 2012-08-08T20:12:56.440 回答