使用 while 循环验证字符串输入

Question

I wanted to validate a string that will be inputted by the user which follows two conditions. The condition would be whether the string is empty or the string has a space char. My current problem is that I can validate the string but it would require me to press enter once more time to reiterate my question "2. Enter Product Name: ".

while (true) {
    cout << "2. Enter Product Name: ";
    if(getline(cin, newNode->product_name)) {
        if ((newNode->product_name).empty() || (newNode->product_name) == " ") {
            cout << "Please enter a valid product name!\n";
            cin.clear();
            cin.ignore(numeric_limits<std::streamsize>::max(), '\n');      
        }
        else {
            break;
        }
    }
} 

Answer 1

Being inside the if statement if(getline(cin, newNode->product_name)) { means that the reading of a line succeeded. Therefore, you don't need the lines

cin.clear();
cin.ignore(numeric_limits<std::streamsize>::max(), '\n');

They will request an extra line to ignore, so remove that lines.