CODEWITHSUNDEEP
c#
Jhon Doe
Jhon Doe

Reputation: 13

Is there a function equivalent to "String.IndexOf(String[])"?

Is there any function that returns the index of the first occurrence of ANY string in a given array like: String.IndexOf(String[])?

or do I need a custom function for it?

For example the below function

 "AppleBananaCherry".IndexOf(new[] {"Banana", "Cherry"});

and 

 "AppleBananaCherry".IndexOf(new[] {"Cherry", "Banana"});

returns 5

Upvotes: 0

Views: 647

Answers (3)

Pavel Anikhouski
Pavel Anikhouski

Reputation: 23228

There is no built-in function for that, String.IndexOf() method accepts only single string or char as parameter, but you can write your own extension method, which uses IndexOf for every item in array, like in the following sample. It also should correctly exclude -1 from intermediate result

public static class Ext
{
    public static int IndexOf(this string thisString, string[] values)
    {
        var index = thisString.Length;
        var isFound = false;
        foreach (var item in values)
        {
            var itemIndex = thisString.IndexOf(item, StringComparison.InvariantCulture);
            if (itemIndex != -1 && itemIndex < index)
            {
                index = itemIndex;
                isFound = true;
            }
        }

        return isFound ? index : -1;
    }
}

The usage example

var index = "AppleBananaCherry".IndexOf(new[] {"Banana", "Cherry"}); //returns 5
index = "AppleBananaCherry".IndexOf(new[] { "Cherry", "Banana" }); //returns 5

Upvotes: 1

JC Olivares
JC Olivares

Reputation: 140

This should 

public static int IndexOf(this string s, string[] values) {
    var found = values
        .Select(v => s.IndexOf(v))
        .Where(index => index >= 0)
        .OrderBy(v => v)
        .Take(1)
        .ToList();
    return found.Count > 0 ? found[0] : -1;
}

EDIT: Removing -1 values

Upvotes: 1

Furkan &#214;zt&#252;rk
Furkan &#214;zt&#252;rk

Reputation: 1416

There is no prepared function but you can use something like this,

var sample = "AppleBananaCherry";
var input = new[] { "Cherry", "Banana" };
var result = input.Min(x => sample.IndexOf(x));

If sample has not any item of input, it returns -1

Upvotes: 2

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