What is the difference between Array.GetLength() and Array.Length?

GetLength takes an integer that specifies the dimension of the array that you're querying and returns its length. Length property returns the total number of items in an array:

int[,,] a = new int[10,11,12];
Console.WriteLine(a.Length);           // 1320
Console.WriteLine(a.GetLength(0));     // 10
Console.WriteLine(a.GetLength(1));     // 11
Console.WriteLine(a.GetLength(2));     // 12

For 1-dimensional arrays Length and GetLength(0) are exactly the same.

For arrays of higher rank Length is the product of all GetLength(0..Rank-1) values, in other words it is always the total number of fields.

The .Length property returns the number of elements in an array, whether it be one dimensional or multidimensional. That is a 2x6 array will have length of 12.

The .GetLength(0) method returns number of elements in the row direction in a multidimensional array. For a 2x6 array that is 2.

The .GetLength(1) method returns number of elements in the column direction in a multidimensional array. For a 2x6 array that is 6.

These do not return an actual element value, as stated by the chosen answer above.

GetLength returns the length of a specified dimension of a mulit-dimensional array.

Length returns the sum of the total number of elements in all the dimensions.

• For a single-dimensional array, Length == GetLength(0)
• For a two-dimensional array, Length == GetLength(0) * GetLength(1)

etc.