February 27, 2019
Execute (a variation of) the code we just reviewed to make sure you understand the mechanism of the increment and decrement operators.
int a = 0, b = 0;
Console.WriteLine("Before changing their values:");
Console.WriteLine($"\ta is {a}\n\tb is {b}\n-----------");
Console.WriteLine("Incrementing, using postfix and prefix operators:");
a++;
++b;
Console.WriteLine($"\ta is {a}\n\tb is {b}\n-----------");
Console.WriteLine("Decrementing, using postfix and prefix operators:");
a--;
--b;
Console.WriteLine($"\ta is {a}\n\tb is {b}\n-----------");
Console.WriteLine("When combining decrementing and incrementing operators with other operations,\nit makes a difference to use postfix or prefix operators!");
int c = a--, d = ++b;
Console.WriteLine($"\ta is {a} (the decrementing took place as expected)\n\tb is {b} (the incrementing took place as expected)\n\tc is {c}" +
$" (c got its value *before* a was decremented)\n\td is {d} (d got its value *after* b was incremented)\n-----------");
Write a while
loop that displays the integers between 1 and 100 at the screen, with a space between them.
Write a while
loop that displays the "*" character 100 times at the screen.
Modify your previous loop, so that a new line character is displayed on the screen every time 10 "*" has been displayed on the screen. That is, your program should display on the screen:
**********
**********
**********
**********
**********
**********
**********
**********
**********
**********
Consider the code we just studied:
Console.WriteLine("Please enter a positive number");
int n = int.Parse(Console.ReadLine());
while (n < 0)
{
Console.WriteLine($"You entered {n}, I asked you for a positive number. Please try again.");
n = int.Parse(Console.ReadLine());
}
Main
method, compile it and execute it.Adapt the code above to perform string validation: ask the user to enter a string, and as long as the user does not enter “Yes” or “No”, ask him/her again to enter a value.