How to Convert big IF condition to small

Question

I have to implement a very big If and else statement in a short and smarter way.

for example :

If(seg.status =="hl"||seg.status =="hl2"||seg.status =="hl3"||seg.status =="hl4"||seg.status =="hl4"||seg.status =="hl5"||seg.status =="hl6"||seg.status =="hl7")

into small and smarter way

You could use the `In` extension method suggested here: https://stackoverflow.com/questions/271398/what-are-your-favorite-extension-methods-for-c-codeplex-com-extensionoverflow?answertab=votes#tab-top — Saragis, Jul 24 '15 at 10:49
possible duplicate of [if statements matching multiple values](http://stackoverflow.com/questions/3907299/if-statements-matching-multiple-values) — dhh, Jul 24 '15 at 10:50

Soner Gönül · Answer 1 · 2015-07-24T10:56:38.577

5

How about adding all your hl strings in a List<string> and check with Any and Contains like;

var list = new List<string>(){"hl", "hl1", "hl2", ...};
if(!list.Any(seg.status.Contains))

As Jon warned, this will return true if your string doesn't match with status, choose

if(list.Contains(seg.status))

instead.

edited Jul 24 '15 at 10:56

answered Jul 24 '15 at 10:49

Soner Gönül

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4

That's an odd way of writing `if (list.Contains(seg.status))` (In fact, it's not quite doing the write thing at the moment... your condition would match a status of "boringstuffhlotherboringstuff" whereas the original condition wouldn't. – Jon Skeet Jul 24 '15 at 10:50
@JonSkeet Right Jon, sorry. Updated. – Soner Gönül Jul 24 '15 at 10:59

score 2 · Answer 2 · answered Jul 24 '15 at 10:55

2

I would put them into a HashSet:

var keywords = new HashSet<String>(StringComparer.InvariantCultureIgnoreCase)
               {
                  "h1", "hl2", ...
               }

And then check if it contains the given word:

if(keywords.Contains(seg.status))
{
   // ToDo: What shall happen?
}

answered Jul 24 '15 at 10:55

Oliver

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what would be the difference using list ? better performance ? – Tharif Jul 24 '15 at 11:03
1

@utility: Yes, just performance, but in case of 10 elements this doesn't matter. But IMHO the type `HashSet` also better describes for what these elements are used for: For fast lookup where order doesn't matter, a list instead would be my preference if order would matter. – Oliver Jul 24 '15 at 11:18

score 1 · Answer 3 · answered Jul 24 '15 at 10:54

1

You could also use regex:

Regex.IsMatch(seg.status, @"hl\d*")

answered Jul 24 '15 at 10:54

Breeze

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score 0 · Answer 4 · answered Jul 24 '15 at 10:57

0

You can try like this

var segList = new List<string>(){"hl", "hl1", "hl2","hl4", "hl15", "hl6","hl7"};

If(segList.contains(seg.status))

answered Jul 24 '15 at 10:57

ssilas777

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score 0 · Answer 5 · answered Jul 24 '15 at 11:26

Do you do this in many places? If so, you could write a little string extension class to make the code more tidy:

public static class StringExt
{
    public static bool MatchesAnyOf(this string text, params string[] targets)
    {
        return targets.Any(target => string.Compare(text, target, StringComparison.OrdinalIgnoreCase) == 0);
    }
}

And you would call it like this:

if (seg.status.MatchesAnyOf("hl", "hl1", "hl2","hl4", "hl15", "hl6","hl7"))

(If you want a case-sensitive comparison, remove the StringComparison.OrdinalIgnoreCase parameter from string.Compare().)

score 0 · Answer 6 · answered Jul 24 '15 at 12:36

If you are confident on the pattern of the test variables naming:

using System.Text.RegularExpressions;

Regex re = new Regex("hl[1|2|3|4|5|6|7]");
string[] test=  {"hl1","hl2","hl3","hl4","hl5","hl6","hl7","hlasdfasdf"};
for(int i = 0; i < test.Length; i++){
    System.Console.WriteLine(test[i] + ":" + (re.IsMatch(test[i])?"match":"does not match"));
}

So in your case:

   if(re.IsMatch(seg.status)){ //...  }

How to Convert big IF condition to small

6 Answers6