Translating a jagged array

The code below translates a jagged array. For a jagged array A, the result is a n*m jagged array, where the outer size is n=max(A[i].Length) and the inner size of each subarray is m=A.GetLength(0).

Remark: Holes after null or incomplete subarrays will be filled with default(T).

Usage:

MyType[][] array = ...;
MyType[][] translated = array.Translate();

For examle:

1. C#

   array = new int[5][] { 
       new int[]  { 5, 6, 7    },
       new int [] { 1, 2, 3, 4 },
       new int [] {            },
       new int [] { 0, 1       },
       null,
   };
   expected = new int[4][] { 
       new int[] { 5, 1, 0, 0, 0 },
       new int[] { 6, 2, 0, 1, 0 },
       new int[] { 7, 3, 0, 0, 0 },
       new int[] { 0, 4, 0, 0, 0 },
   };

2. C#

   array = new int[2][] { 
       null,
       null,
   };
   expected = new int[1][] { 
       new int[] { 0, 0 },
   };

   
   

   For nullable types, there would be null instead of 0.

   
   
   C#

   public static class JaggedArrayExtensions
   { 
       /// <summary>
       /// Translates a given jagged array. Holes after null
       /// or incomplete subarrays will be fileld with default(T).
       /// </summary>
       /// <typeparam name="T">Type of elements in the array</typeparam>
       /// <param name="array">The array to translate</param>
       /// <returns>A n*m jagged array, where the outer size is n=max(A[i].Length) and 
       /// the inner size of each subarray is m=A.GetLength(0).</returns>
       public static T[][] Translate<t>(this T[][] array)
       {
           if (array == null)
               throw new ArgumentNullException();
           if (array.Length == 0)
               return new T[0][];
           int columnCount = array.Max(sub => sub == null ? 1 : sub.Length);
           int rowCount = array.Length;
           T[][] res = new T[columnCount][];
           for (int i = 0; i < columnCount; i++)
           {
               res[i] = new T[rowCount];
               for (int j = 0; j < rowCount; j++)
               {
                   if (array[j] == null || i >= array[j].Length)
                       res[i][j] = default(T);
                   else
                       res[i][j] = array[j][i];
               }
           }
           return res;
       }
   }