An array is used to store a collection of data of the same type. This can be used as a single variable that holds multiple values, or a collection of variables.
Jagged arrays contain elements that are arrays itself. Example of declaration and initialization of jagged array:
```csharp
int[][] array = new int[2][];
```
Each element of jagged array can contains array of different length, ex:
```csharp
array[0] = new int[2];
array[1] = new int[4];
array[0][0] = 1;
array[0][1] = 2;
array[1][0] = 1;
array[1][1] = 2;
array[1][2] = 3;
array[1][3] = 4;
```
As you see the array contains 2 other arrays which respectively contain 2 and 4 elements. Above code can be written shorter by using different format:
```csharp
int[][] array =
{
new int[] {1,2},
new int[] {1,2,3,4}
};
```
It's important to remember that types of subarrays must be the same as type of main array. To access specific element of jagged array you should use `array[x][y]` syntax where x is an index of main array which indicates subarray and y is index of subarray which indicates element within that subarray.
```csharp
Console.Write(array[0][0]); // Displays 1 (first element of first subarray)
Console.Write(array[1][2]); // Displays 3 (third element of second subarray)
Console.Write(array[1][0]); // Displays 1 (first element of second subarray)
Arrays can have more than one dimension (every element will be represented by more than one index). Example of declaration and initialization of two dimensional array:
```csharp
string[,] weekDays = new string[2, 3];
```
Having two dimensional array we need to use two indexes to represent the position of element:
```csharp
weekDays[0,0] = "monday";
weekDays[0,1] = "montag";
weekDays[0,2] = "lundi";
weekDays[1,0] = "tuesday";
weekDays[1,1] = "dienstag";
weekDays[1,2] = "mardi";
```
To check number of dimensions we can use Rank property:
