Question

Does c# have a function that returns a boolean for expression : if(value.inRange(-1.0,1.0)){}?

Answer 1

Description

I suggest you use a extension method.

Extension methods enable you to “add” methods to existing types without creating a new derived type, recompiling, or otherwise modifying the original type.

You can create this extension method in a generic way (thx to digEmAll and CodeInChaos, who suggest that). Then you can use that on every object that implements IComparable.

Solution

public static class IComparableExtension
{
    public static bool InRange<T>(this T value, T from, T to) where T : IComparable<T>
    {
        return value.CompareTo(from) >= 1 && value.CompareTo(to) <= -1;
    }
}

then you do this

double t = 0.5;
bool isInRange = t.InRange(-1.0, 1.0);

Update for perfectionists

After an extensive discussion with @CodeInChaos who said

I’d probably go with IsInOpenInterval as suggested in an earlier comment. But I’m not sure if programmers without a maths background will understand that terminology.

You can name the function IsInOpenInterval too.

More Information

• MSDN – Extension Methods (C# Programming Guide)
• MSDN – IComparable Interface