Compare a string to multiple strings

Question

Is there a way to compare two strings to another string at once?

Example:

string1 == string2 && string3;

(I know this isn't the way, just a representation of what I mean)

`&` looks like the VB.NET [concatenation operator](http://msdn.microsoft.com/en-us/library/te2585xw.aspx). Is that intended? — Tim Schmelter, Mar 18 '14 at 15:44
@Bolu `(string1 == string2)` is bool then `(bool) == string3`. — Alessandro D'Andria, Mar 18 '14 at 15:47
@TunZarniKyaw just comparing the contents, not comparing two concatenated strings. — Callum, Mar 18 '14 at 15:49
Bolu your codes are doesn't even compile. You are lucky because there is no downvote on comments. — Selman Genç, Mar 18 '14 at 15:56
@Selman22, I was suggesting how should these be represented in just one sentence..... if it exists..... — Bolu, Mar 18 '14 at 15:58
@Callum, just for my peace of mind, you know you can use `string1 == string2 && string1 == string3;` and you are just looking for a short line, right? — Bolu, Mar 18 '14 at 16:26
@Bolu yes, I was just trying to find out if there was an easier way as it is a line I have to write quite a lot — Callum, Mar 18 '14 at 16:31

score 8 · Accepted Answer · answered Mar 18 '14 at 15:42

8

Generally, no, there is no way to do this that resembles the way you asked to do it.

However, if the strings to compare with are in a collection of some kind, you can do this:

 if (stringCollection.All(s => s == string1) )

answered Mar 18 '14 at 15:42

Joel Coehoorn

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That or `if (stringCollection.Any(s => s == string1) )`. All returns true if all elements match. Any returns true if one or more elements match – Ricardo Appleton Mar 18 '14 at 15:52
Sorry just want to clarify, is that comparing all the strings in the collection to one another, or just one to all the others? – Callum Mar 18 '14 at 15:52
@Callum It compares one to all the others... but since you used an _AND_ operator, it should match what your pseudocode was looking for here. – Joel Coehoorn Mar 18 '14 at 15:55
@Callum: the portion `(s => s... ` refers to your other strings, string2 and 3 which should be in a collection – Ricardo Appleton Mar 18 '14 at 15:55
@JoelCoehoorn Yeah that's what I was after, but since they aren't already in a collection it will probably be easier to just do two comparisons. Thanks anyway! – Callum Mar 18 '14 at 15:57

Andre Figueiredo · Answer 2 · 2014-03-18T16:56:34.747

0

Besides Linq's All method, you can do also with List methods, like TrueForAll

    string searchString = "hi";
    var listStrings = new List<string>() { "hi", "there" };
    bool allOfThem = listStrings.TrueForAll(x => x == searchString);
    bool atLeastOne = listStrings.Contains(searchString);

edited Mar 18 '14 at 16:56

answered Mar 18 '14 at 15:53

Andre Figueiredo

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score 0 · Answer 3 · answered Mar 18 '14 at 16:03

0

If you don't want to deal with putting your values into a collection or list, you could do an extension method like this:

static class extensions
{
    private static bool InSet(this string s, params string[] p )
    {
        return p.Contains(s);
    }
}

Then when you want to test if a string matches a value in a set you can do this:

if (String1.InSet(String2, String3))
{
    // do something.
}

answered Mar 18 '14 at 16:03

William Leader

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I would like to add, that this solution works with any number of parameters. – William Leader Mar 18 '14 at 16:06

Compare a string to multiple strings

3 Answers3