398: Highlights

If you want to create a one-dimensional array, then instantiate the following pattern:
```
Array new: number of elements 
```
If you have an array, and you want to store an expression's value in the array, then instantiate the following pattern:
```
array name at: index put: expression 
```
If you have values stored in an array, and you want to retrieve one of those values, then instantiate the following pattern:
```
array name at: index 
```

If you want to iterate over the elements in an array, then instantiate one of the following patterns:

array name do: [:element | ... element ...] 

1 to: array name size  
  do: [:index | ... (array name at: index) ...]

If you want to iterate over the elements in an array, and you want to include the results of a previous iteration in each computation, then instantiate the following pattern:
```
an Array instance  
  inject: initial value  
  into: [:previousResult :nextElement | statements]   
```
If you want to create a two-dimensional array, then create an array in which the elements are themselves arrays.