0
我在使用cin.peek
进行验证时遇到了问题。 我想要做的只是从用户获得积极的int
。我使用下面的代码 (我不得不使用功能) 尝试(getwholenum
和getposnum
做工精细没有getnum
功能):cin.peek输入验证
#include <iostream>
#include <string>
using namespace std;
double getposnum(double &); //function protoype for getting positive number
double getwholenum(double &); //function protoype for getting a whole number
double getnum(double &); //function protoype for getting an int
int main()
{
static double x;
cout << "please give me a number" << endl;
cin >> x;
cin.ignore();
x = getnum(x);
cout << x;
cin.get();
}
double getnum(static double & x) //validation for int only (no char)
{
// cin checks if the stream has failed
// cin = true, cin = false !cin
while (!(cin >> x))
{
cout << "Input was not a number" << endl << "Enter a VALID number! ";
cin >> x;
cin.clear();
cin.ignore();
}
cout << "it's not a letter";
getposnum(x);
return x;
} // if i dont put in a letter nothing would happen
double getposnum(static double & x) // another function to get a positive number
{
while (x < 0)
{
cout << "negative" << endl;
cin >> x;
cin.ignore();
}
cout << "positive" << endl;
getwholenum(x);
return x;
}
double getwholenum(static double & x)
{
while (x != static_cast<int>(x)) // forcing a double into an int if it's equal then the number was an in
{
cout << "not a whole number" << endl;
cin >> x;
cin.ignore();
}
cout << "whole number";
return x;
}
_“我有麻烦......“很含糊。你可以请更具体吗? –
对不起,这是我在这里的第一个问题 – Moya
所以我想验证整个积极int,但是当我不把一封信没有什么会发生 – Moya