How to gain memory consumption for array a with n rows and m columns?

Question

How to get the allocated space in memory for array A with N rows and M columns in C# ?

is there any function or something like this ?

I search several times in internet; but i can't find any good answer for my question that i understand that.

_" i can't find any good answer for my question that i understand that."_ I don't understand _your question_. — Tim Schmelter, Jul 29 '14 at 12:32
You need to be more clear about what you want. Do you want to reclaim memory after freeing an array or what? — LazyOfT, Jul 29 '14 at 12:33
Are you trying to allocate an array or resize an existing array? — Chris Hinton, Jul 29 '14 at 12:40
Possible duplicate http://stackoverflow.com/questions/1128315/find-size-of-object-instance-in-bytes-in-c-sharp — Moti Azu, Jul 29 '14 at 12:46
possible duplicate of [Getting the size of a field in bytes with C#](http://stackoverflow.com/questions/207592/getting-the-size-of-a-field-in-bytes-with-c-sharp) — DmitryG, Jul 29 '14 at 12:48

score 2 · Accepted Answer · answered Jul 29 '14 at 12:57

If you want to know that how much memory a two dimensional array will consume, then it will depend on the data type.

e.g. if you have an array of 3 rows and 4 columns with type int then as an int consumes 32 bit or 4 bytes. So whole array will consume 32*3*4 = 384 bits or 4*4*3 = 48 bytes.

For simple calculation you can use following code for getting the memory consumption by different value types:

var size = BitConverter.GetBytes(value).Length; // here value can be any value type.

score 2 · Answer 2 · edited May 23 '17 at 12:20

You can't know the exact size occupied in memory by the entire array with all mem-paddings and etc. You can use the following approach to estimate of how many bytes in memory occupied by all array cells.:

long size1 = GetArrayElementsSizeInMemory(new int[] { 1, 2 }); // 8 bytes
long size2 = GetArrayElementsSizeInMemory(new int[,] { { 1 }, { 2 }, { 3 } }); // 12 bytes
long size3 = GetArrayElementsSizeInMemory(new int[][] { new int[] { 1, 2 }, new int[] { 3, 4 } }); // 16 bytes
//...
static long GetArrayElementsSizeInMemory(Array array) {
    return array.Length * GetArrayElementSize(array);
}
static long GetArrayElementSize(Array array) {
    var elemenType = array.GetType().GetElementType();
    return elemenType.IsValueType ? Marshal.SizeOf(elemenType) : IntPtr.Size;
}

How to gain memory consumption for array a with n rows and m columns?

2 Answers2