Question

In C#, I often have to limit an integer value to a range of values. For example, if an application expects a percentage, an integer from a user input must not be less than zero or more than one hundred. Another example: if there are five web pages which are accessed through Request.Params["p"], I expect a value from 1 to 5, not 0 or 256 or 99999.

I often end by writing a quite ugly code like:

page = Math.Max(0, Math.Min(2, page));

or even uglier:

percentage =
    (inputPercentage < 0 || inputPercentage > 100) ?
    0 :
    inputPercentage;

Isn’t there a smarter way to do such things within .NET Framework?

I know I can write a general method int LimitToRange(int value, int inclusiveMinimum, int inlusiveMaximum) and use it in every project, but maybe there is already a magic method in the framework?

If I need to do it manually, what would be the “best” (ie. less uglier and more fast) way to do what I’m doing in the first example? Something like this?

public int LimitToRange(int value, int inclusiveMinimum, int inlusiveMaximum)
{
    if (value >= inclusiveMinimum)
    {
        if (value <= inlusiveMaximum)
        {
            return value;
        }

        return inlusiveMaximum;
    }

    return inclusiveMinimum;
}

Answer 1

I see Mark’s answer and raise it by a this:

public static class InputExtensions
{
    public static int LimitToRange(
        this int value, int inclusiveMinimum, int inclusiveMaximum)
    {
        if (value < inclusiveMinimum) { return inclusiveMinimum; }
        if (value > inclusiveMaximum) { return inclusiveMaximum; }
        return value;
    }
}

Usage:

int userInput = ...;

int result = userInput.LimitToRange(1, 5)

See: Extension Methods