JavaScript StartsWith / EndsWith

This will test for IsNullOrEmpty for all objects including string and you can specify multiple values including multiple types.  E.g. “”, null, -1 as a prarms based object or array

public static bool IsNullOrEmpty(object obj, params object[] emptyValues)
{
    object[] defaultEmptyValues = new object[] { "", null, -1 };

    if (emptyValues == null)
    {
        emptyValues = defaultEmptyValues;
    }
    foreach (object emptyValue in emptyValues)
    {
        if (obj == emptyValue) return true;
    }
    return false;

}