Array as a Map

Suppose that:

• The KeyType is an integer.

• The size of the domain (largest possible key minus smallest) is not too large.

In this case, the best map to use is an array:

• O(1) and very fast.

• very simple code: a[i]

• no space required for keys (key is the array index).

When it is applicable, use an array in your programs rather than a switch statement:

• runs faster

• uses less storage

• better software engineering