Thread: Experts please help a student! Basic C++ question.

this is a part of my programme

Code:

class Impedence
{
protected:
    int R1, R2, X1, X2;   
public:
	void enterNum(void);
};
void Impedence::enterNum(void)
{

        cout<<"Enter real part of impendence A: ";
	cin>>R1;
        cout<<"Enter imaginary part of impedence A: ";
	cin>>X1;
	cout<<"Enter real part of impedence B: ";
	cin>>R2;
	cout<<"Enter imaginary part of impedence B: ";
	cin>>X2;
}

how do i modify it such that the user can only enter positive integer?
invalid input will stop the next statement and return to the first.
for eg. if the user entered alphabet "a" or any other alphabet it will show "Please enter an integer value!" the programme will then loop back to the first cout.

Read your book on do...while loops perhaps?

It may also be better, in this case, to read a whole line of input into a string (using istream's getline() method), interpret the input to see if it is valid, and only then extract the values needed

Also, if you want to input a positive value, why not store it in an unsigned type?