Why does my first if statement work, but my else if statement after it doesn't work

Question

Why does my first if statement work, but my else if statement doesn't? Just hoping someone can see something I may be missing. When I enter in a time between 800 and 1800 the code continues fine, but when I enter in 600 it jumps to my else statement that I entered in an illegal format.

if ((time_start >= 800) && (time_start <= 1800))
    {
    cout << "How many minutes did your call last? ";
    cin >> minutes;
    cost = minutes * 0.40;
    cout << setprecision(2) << fixed << cost;
    system("pause");
    keepgoing = false;
} 
else if ((time_start < 800) && (time_start > 1800))
{
    cout << "How many minutes did your call last? ";
    cin >> minutes;
    cost = minutes * 0.25;
    cout << setprecision(2) << fixed << cost;
    system("pause");
    keepgoing = false;
}

Answer 1

else if ((time_start < 800) && (time_start > 1800))

一个数字不可能小于800且大于1800。我假设您的意思是：

else if ((time_start < 800) || (time_start > 1800))

Answer 2

You've got a 'logic bug' : use || instead of && in else if . It's simply impossible for a number to be less than 800 and greater than 1800 at the same time .

Answer 3

As soon as I asked this question I realized my second else if statement should be an or || statement instead of &&.

Answer 4

change

else if ((time_start < 800) (time_start > 1800

to

else if ((time_start < 800) || (time_start > 1800

Answer 5

You can simplify the code to this, else statement is not needed. Store the value in coeficient variable, that's needed to be defined before

// else coef (default value)
float coef = 0.25;
if ((time_start >= 800) && (time_start <= 1800))
{
    coef = 0.40; // if true
}
cout << "How many minutes did your call last? ";
cin >> minutes;
// use coef here and remove duplicate calls
cost = minutes * coef;
cout << setprecision(2) << fixed << cost;
system("pause");
keepgoing = false;