CODEWITHSUNDEEP
c#
General Grey
General Grey

Reputation: 3688

C# syntax if (value=this || this|| this) do this

just to throw some code out there

string answer = "hotel"
if (answer == "house"|| answer == "hotel" || answer =="appartment")
{
    DoSomething()
}

I was wondering if there was some way to shorten it to

string answer = "hotel"
if (answer == "house"|| "hotel" || "appartment")
{
    DoSomething()
}

I am aware of the switch statement 

switch (answer)
{
    case "house":
    case "hotel":
    case "appartment": DoSomething();
        break;
    default :DoNothing();
}

I am just wondering if there is some syntax sugar like what I described above.

Upvotes: 3

Views: 322

Answers (10)

Allrameest
Allrameest

Reputation: 4492

I would use an extension method like this:

public static bool In<T>(this T item, params T[] items)
{
    return items.Contains(item);
}

Use it like this:

if ("hotel".In("house", "hotel", "apartment"))
or
if (1.In(1,2))

Upvotes: 0

YoryeNathan
YoryeNathan

Reputation: 14522

public static bool Any<T>(T item, params T[] items)
{
    return items.Contains(item);
}

Usage:

if (Any(6, 1, 2, 3, 4, 5, 6, 7))
{
    // 6 == 6
}

if (Any("Hi", "a", "cad", "asdf", "hi"))
{
}
else
{
    // "Hi" != "hi" and from anything else.
}

Or:

public string[] items = new string[] {"a", "cad", "asdf", "hi"};

...

if (Any("Hi", items))
{
    Works just as well.
}

You can also have more advanced comparison. For example, if you wanted:

if (person.Name == p1.Name ||
    person.Name == p2.Name ||
    person.Name == p3.Name ||
    person.Name == p4.Name ||
    person.Name == p5.Name || ...)
{
}

You can have:

public static bool Any<T>(T item, Func<T, T, bool> equalityChecker, params T[] items)
{
    return items.Any(x => equalityChecker(item, x));
}

And do:

if (Any(person, (per1, per2) => p1.Name == p2.Name, p1, p2, p3, p4, p5, ...)
{
}

EDIT

If you insist, you can make it, of course, an extension method:

public static bool Any<T>(this T item, params T[] items)
{
    return items.Contains(item);
}

Usage:

var b = 6.Any(4, 5, 6, 7); // true

And the same logic of adding the keyword "item" in the signature goes for the overload with the equalityChecker.

Upvotes: 4

Gladen
Gladen

Reputation: 802

I normally use a switch statement in this case, but as already said in a few answers above you can put the results in an list or array and check it that way.

Upvotes: 0

Oblivion2000
Oblivion2000

Reputation: 616

Consider adding an extension method that will accept any strings...

string answer = "hotel"
if (answer.EqualsAny("house", "hotel", "appartment"))
{
    DoSomething()
}
// Extending the thought to another version
if (answer.EqualsAll("house", "hotel", "appartment"))
{
    DoSomething()
}

public static class Extensions
{
    public static bool EqualsAny(this string value, params string[] compareAgainst)
    {
        foreach (var element in compareAgainst)
        {
            if(value == element)
               return true;
        }
        return false;
    }
    public static bool EqualsAll(this string value, params string[] compareAgainst)
    {
        foreach (var element in compareAgainst)
        {
            if(value != element)
                return false;
        }
        return true;
    }
}

Upvotes: 1

avani gadhai
avani gadhai

Reputation: 460

If your comparison parameters are fixed, you can opt for ENUM with Flags. Ref MSDN. Then you can have the desired behavior. You can also refer to this post

Upvotes: 0

jussinen
jussinen

Reputation: 688

You could use an array and use Contains.

So in your example:

string answer = "hotel";
string[] acceptable = new string[]{"house", "hotel", "appartment"};
if (acceptable.Contains(answer)){
    DoSomething();
}

Upvotes: 7

Tigran
Tigran

Reputation: 62256

You can do like 

if(new string[]{"house","hotel","appartment"}.Contains(asnwer))
{
...
}

or 

if(new List<string>(){"house","hotel","appartment"}.Any(x=>x == answer)
{
}

Can add this like an extension method too, and use...

Upvotes: 1

bjornruysen
bjornruysen

Reputation: 850

Only thing I can think of is to work with a list or array:

List<String> words = new List<String> { "house", "hotel", "appartment" };
String answer = "house";

if (words.Contains(answer))
{
   DoSomething();
}

Upvotes: 2

Nikhil Agrawal
Nikhil Agrawal

Reputation: 48568

Create a Global List and just check it in any method.

List<string> validAnswers = new List<string> {"house", "house1", "apartment"};

if (validAnswers.Contains(answer))
    DoSomething();

In this case your List will not be generated every time answer is checked

Upvotes: 3

goric
goric

Reputation: 11885

It is possible to use some syntactic sugar for this:

if((new[]{"house", "hotel", "apartment"}).Contains(answer))
{
}

Note that this will create a new array on the fly, so will potentially be more expensive than just the Boolean checks.

Upvotes: 8

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