C#: how can I make all these "else if" statements more condensed and how can I optimize my-CodePudding

Okay, I have a load of else if statements, is there a way to condense them into fewer lines of code? Like make one if statement for all of it? And what ways could I make my code more optimize and easier to read?

int x;
int y;
int time = 0;

Random rng = new Random();
int hrand_num = rng.Next(-24000, 24000);
int vrand_num = rng.Next(-24000, 24000);

x = hrand_num;
y = vrand_num;

while (true)
{
    ConsoleKey key = Console.ReadKey().Key;
             
    if (key == ConsoleKey.UpArrow)
    {
        y = y   2000;
    }
    else if (key == ConsoleKey.DownArrow)
    {
        y = y - 2000;
    }
    else if (key == ConsoleKey.LeftArrow)
    {
        x = x - 1000;
    }
    else if (key == ConsoleKey.RightArrow)
    {
        x = x   1000;
    }

    // Circumnavigate Players Position.

    // North and South
    if (y >= 24001)
    {
        y = -24000;
    }
    else if (y <= -24001)
    {
        y = 24000;
    }
    // West and East
    else if (x >= 24001)
    {
        x = -24000;
    }
    else if (x <= -24001)
    {
        x = 24000;
    }

    // Setting Time Zones
    if (x >= -2000 && x <= 0 )
    {
        time = 0;
    }
    else if (x >= 1 && x <= 2000)
    {
        time = 1;
    }
    else if (x >= 2001 && x <= 4000)
    {
        time = 2;
    }
    else if (x >= 4001 && x <= 6000)
    {
        time = 3;
    }
    else if (x >= 6001 && x <= 8000)
    {
        time = 4;
    }
    else if (x >= 8001 && x <= 10000)
    {
        time = 5;
    }
    else if (x >= 10001 && x <= 12000)
    {
        time = 6;
    }
    else if (x >= 12001 && x <= 14000)
    {
        time =  7;
    }
    else if (x >= 14001 && x <= 16000)
    {
        time =  8;
    }
    else if (x >= 16001 && x <= 18000)
    {
        time =  9;
    }
    else if (x >= 18001 && x <= 20000)
    {
        time =  10;
    }
    else if (x >= 20001 && x <= 22000)
    {
        time =  11;
    }
    else if (x >= 22001 && x <= 24000)
    {
        time = 12;
    }
    else if (x == -24000 && x <= -22001)
    {
        time = 13;
    }
    else if (x >= -22000 && x <= -20001 )
    {
        time = 14;
    }
    else if (x >= -20000 && x <= -18001)
    {
        time = 15;
    }
    else if (x >= -18000 && x <= -16001)
    {
        time = 16;
    }
    else if (x >= -16000 && x <= -14001)
    {
        time =  17;
    }
    else if (x >= -14000 && x <= -12001)
    {
        time = 18;
    }
    else if (x >= -12000 && x <= -10001)
    {
        time = 19;
    }
    else if (x >= -10000 && x <= -8001)
    {
        time =  20;
    }
    else if (x >= -8000 && x <= -6001)
    {
        time = 21;
    }
    else if (x >= -6000 && x <= -4001)
    {
        time = 22;
    }
    else if (x >= -4000 && x <= -2001)
    {
        time = 23;
    }

    Console.SetCursorPosition(Console.CursorLeft, Console.CursorTop -2);
    Console.WriteLine($"X: {x,6} Y: {y,6} Time: {time,3}");
    Console.SetCursorPosition(Console.CursorLeft, Console.CursorTop   1);
}

CodePudding user response：

Assuming that you are using C# 8.0 you may have a look at the switch statement and switch expressions: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/switch-expression (additionaly the patterns documentation is also helpful: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/operators/patterns)

So you could write something like:

switch (key)
{
  case ConsoleKey.UpArrow:
    y=y 2000;
    break;
  // [...]
}

time = x switch
{
  >= -2000 and <= 0 => 0,
  >= 1 and <= 2000 => 1
  // [...]
};

CodePudding user response：

I would suggest that you take advantage of:

a switch statement for interpreting the arrow key
- comparing the switch statement to an if loop, you can think of the first case as being the if condition and the remaning cases as being the else if conditions
Math.Abs( ) and Math.Sign( ) for circumnavigating the player's position
- Math.Abs( ) returns the absolute value of the variable; e.g. will Math.Abs(x) return 5 both for x = 5 and x = -5
- Math.Sign( ) returns the sign of the value; if the value is a negative number, it returns -1; if it's a positive number, it returns 1; if it's neither (0), it returns 0. This helps us determine the wanted sign of the updated value.
a switch expression for setting the time
- seeing as the time value alone is determined by x in the end, you can use a switch expression rather than a switch statement to determine its value. The switch expression says that you want to determine the value of time based on the value of x; and each following condition is compared to x (<= -22001 is computed as x <= -22001). If the condition evaluates to true, the provided value is set as the value of time (=> 13 then sets time = 13).

It could be implemented like this:

int x;
int y;
Random rng = new Random();
int hrand_num = rng.Next(-24000, 24000);
int vrand_num = rng.Next(-24000, 24000);
x = hrand_num;
y = vrand_num;

while (true)
{
    switch (Console.ReadKey().Key)
    {
        case ConsoleKey.UpArrow:
            y  = 2000;
            break;
        case ConsoleKey.DownArrow:
            y -= 2000;
            break;
        case ConsoleKey.LeftArrow:
            x -= 1000;
            break;
        case ConsoleKey.RightArrow:
            x  = 1000;
            break;
    }

    // Circumnavigate Players Position.
    // North and South
    if (Math.Abs(y) > 24000)
    {
        y = -(Math.Sign(y) * 24000);
    }
    //West and East
    else if (Math.Abs(x) > 24000)
    {
        x = -(Math.Sign(x) * 24000);
    }

    // Setting Time Zones
    var time = x switch
    {
        <= -22001   => 13,
        <= -20001   => 14,
        <= -18001   => 15,
        <= -16001   => 16,
        <= -14001   => 17,
        <= -12001   => 18,
        <= -10001   => 19,
        <= -8001    => 20,
        <= -6001    => 21,
        <= -4001    => 22,
        <= -2001    => 23,
        <= 0        => 0,
        <= 2000     => 1,
        <= 4000     => 2,
        <= 6000     => 3,
        <= 8000     => 4,
        <= 10000    => 5,
        <= 12000    => 6,
        <= 14000    => 7,
        <= 16000    => 8,
        <= 18000    => 9,
        <= 20000    => 10,
        <= 22000    => 11,
        <= 24000    => 12,
        _ => 0
    };

    Console.WriteLine($"X: {x,6} Y: {y,6} Time: {time,3}");

I would also suggest introducing some constants; particularily for the value 24000.