Umbraco-CMS/src/Umbraco.Core/Routing/WebPath.cs

using System;
using System.Text;

namespace Umbraco.Cms.Core.Routing
{
    public class WebPath
    {
        public const char PathSeparator = '/';

        public static string Combine(params string[] paths)
        {
            if (paths == null)
            {
                throw new ArgumentNullException(nameof(paths));
            }

            if (paths.Length == 0)
            {
                return string.Empty;
            }

            var sb = new StringBuilder();

            for (var index = 0; index < paths.Length; index++)
            {
                var path = paths[index];
                var start = 0;
                var count = path.Length;
                var isFirst = index == 0;
                var isLast = index == paths.Length - 1;

                // don't trim start if it's the first
                if (!isFirst && path[0] == PathSeparator)
                {
                    start = 1;
                }

                // always trim end
                if (path[path.Length - 1] == PathSeparator)
                {
                    count = path.Length - 1;
                }

                sb.Append(path, start, count - start);

                if (!isLast)
                {
                    sb.Append(PathSeparator);
                }
            }

            return sb.ToString();
        }
    }
}