How do I find the closest array element to an arbitrary (non-member) number?

Question

Seemingly similar questions: \"Finding closest number in an array\" (in Java) and \"find nearest match to array of doubles\" (actually a geography problem).

Answer 1

Something like this:

double[] values = new double[]
{
    1.8,
    2.4,
    2.7,
    3.1,
    4.5
};

double difference = double.PositiveInfinity;
int index = -1;

double input = 2.5;

for (int i = 0; i < values.Length; i++)
{
    double currentDifference = Math.Abs(values[i] - input);

    if (currentDifference < difference)
    {
        difference = currentDifference;
        index = i;
    }

    // Stop searching when we've encountered a value larger
    // than the inpt because the values array is sorted.
    if (values[i] > input)
        break;
}

Console.WriteLine("Found index: {0} value {1}", index, values[index]);