C＃foreach内部while循环

Question

I have a list with strings, I want to use Levenstein algorithm(or any other) to check if the new record I am trying to insert into a database is similar to what I have already in the database. Algorithm should go thru every single item in the list and compare with one I want to insert. If similarity is high, then break the loop and return.

I have started, but not sure If i am on the right way. How to break from foreach loop in while loop?

public static bool IsSimilarValuesExist(string value)
    {
        bool result = false;
        string valueFromList = string.Empty;
        double similarityProduct = 0;

        List<string> products = ServicesMail.GetProducts();

        IStringMetric metric = new Levenstein();
        while (metric.GetSimilarity(value, valueFromList) < 5)
        {
            foreach (var item in products)
            {
                // If current item not similar, continue
                // If is similar, break from loop and assign current compareValue to similarityProduct
            }
        }

        return result;
    }

Answer 1

How to break from foreach loop in while loop?

Don't. Solve the problem by refactoring. Suppose you were to replace the inner loop with a method. What would the inputs and outputs of that method have to be in order to make the outer loop correct? Now actually write a method with those semantics, and your problem is solved.

Answer 2

add an extra variable inside your while to indicate whether to break out of the outer loop

while(...)
{
    bool shouldBreak = false
    foreach(...)
    {
        shouldBreak = true;
        break;
    }

    if (shouldBreak)
         break;
}

Answer 3

Sorry for a question. Looked at the problem different way. Found a different solution.

        public static bool IsSimilarValuesExist(string value)
    {
        var result = false;

        double productSimilarity = 0;
        double publisherSimilarity = 0;

        List<string> products = FilterListWithFirstOrSecondCharacter(value, ServicesMail.GetAllProductNames());
        List<string> publishers = FilterListWithFirstOrSecondCharacter(value, ServicesMail.GetAllPublisherNames());

        IStringMetric metric = new Levenstein();

        foreach (var item in products)
        {
            if (metric.GetSimilarity(value, item) * 100 > 80)
            {
                productSimilarity = metric.GetSimilarity(value, item) * 100;
            }
        }

        foreach (var item in publishers)
        {
            if (metric.GetSimilarity(value, item) * 100 > 80)
            {
                publisherSimilarity = metric.GetSimilarity(value, item) * 100;
            }
        }

        var averageSimilarity = productSimilarity * publisherSimilarity / 2;
        if (averageSimilarity >= 80)
        {
            result = true;
        }

        return result;
    }