Eliminating Multiple If Statements For Pulling A Specific Object Property

Question

Model:

public class ServiceHours
{
    public int Id { get; set; }
    ...
    public TimeSpan? Monday { get; set; }
    public TimeSpan? Tuesday { get; set; }
    public TimeSpan? Wednesday { get; set; }
    public TimeSpan? Thursday { get; set; }
    public TimeSpan? Friday { get; set; }
    public TimeSpan? Saturday { get; set; }
    public TimeSpan? Sunday { get; set; }
}

I'm currently iterating through a list of "service hour" objects (they can hold an optional start time for 1 or multiple days of the week). I want to be able to dynamically grab the value that corresponds to the DayOfWeek enum from a DateTime object.

This works but isn't very elegant

var today = DateTime.Today.DayOfWeek;

foreach (var item in myItems)
{
    var time = new TimeSpan?();

    if (today == DayOfWeek.Monday)
        time = item.Monday;
    else if (today == DayOfWeek.Tuesday)
        time = item.Tuesday;
    else if (today == DayOfWeek.Wednesday)
        time = item.Wednesday;
    else if (today == DayOfWeek.Thursday)
        time = item.Thursday;
    else if (today == DayOfWeek.Friday)
        time = item.Friday;
    else if (today == DayOfWeek.Saturday)
        time = item.Saturday;
    else if (today == DayOfWeek.Sunday)
        time = item.Sunday;

    ...
}

UPDATE: I ended up using reflection at the time, but this was a very poor, naive design to begin with and this question should've been posted to Code Review anyways - This question should be disregarded, just adding this notice in case any others come along. Thanks to those who attempted to help out regardless of the terrible question!

The code does not make a whole lot of sense. You have a variable named `object`? I _sincerely_ doubt that. What is the intention of this code? It feels like an [XY Problem](https://meta.stackexchange.com/questions/66377/what-is-the-xy-problem) — maccettura, Mar 28 '18 at 20:25
This sounds like a [Code Review](https://codereview.stackexchange.com/) and that would make it off-topic for this site — Nkosi, Mar 28 '18 at 20:33
Alternatively you can use switch-case or create a Dictionary where keys are values of DayOfWeek and values are values of "object". — M Bakardzhiev, Mar 28 '18 at 20:37
You _could_ put them in an array and then cast the `DayOfWeek` enum to an `int` to select from that array BUT it wouldn't be much better and it would require another allocation on the heap. — Ian Mercer, Mar 28 '18 at 20:42
If you want to call your object 'object' it needs to be `@object` but don't ever do that :) — Ian Mercer, Mar 28 '18 at 20:43

Cory · Answer 1 · 2018-03-28T21:16:38.107

If you are able to modify the class of the object that makes up your objectList variable, then try using a Dictionary<DayOfWeek, TimeSpan?> in that class. DayOfWeek would be the key and TimeSpan? would be the value. This would simplify the class as well as eliminate the long if-else logic.

Also, if I'm not mistaken, this method would also be faster than using reflection and wouldn't rely on the property names of your object to be spelled exactly the same of the days of the week in DayOfWeek (if you needed to refactor for some reason in the future).

Here is an example:

static void Main(string[] args)
{
    List<WeekObject> weekObjs = new List<WeekObject>();

    foreach (var obj in weekObjs)
    {
        SaveTime(obj.ID, obj.weekDictionary[DateTime.Today.DayOfWeek]);
    }
}

class WeekObject
{
    public int ID { get; set; }
    public Dictionary<DayOfWeek, TimeSpan?> weekDictionary { get; set; } = new Dictionary<DayOfWeek, TimeSpan?>();

    public WeekObject ()
    {
        // Initialize dictionary here if you'd like
        weekDictionary.Add(DayOfWeek.Sunday, null);
    }
}

public static void SaveTime(int ID, TimeSpan? timeSpan)
{
    // Your code here
}

Tigran · Accepted Answer · 2018-03-28T20:39:37.187

0

Something like this probably (did not compiled this code though)

object.GetType().GetProperty(today.DayOfWeek.ToSring()).GetValue(object)

use reflection to get property value,with only condition that DayOfWeek enum member has to have exact name of the property present in object type.

edited Mar 28 '18 at 20:39

answered Mar 28 '18 at 20:37

Tigran

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It seems like reflection is a bad idea here, we should figure out some more details from the OP – maccettura Mar 28 '18 at 20:38

Eliminating Multiple If Statements For Pulling A Specific Object Property

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