ex28.3.txt

1. Global variables could work, but when the number of stations grows it can
easily pollute the global name space and extra care has to be taken to avoid name
conflicting. Generally speaking, it becomes harder to maintain when the number
of stations grows.

2. Table mapping is good enough for static mapping. It does not create name
conflicts in the global name space. However, when the URL is generated from the
name of the station procedurally, table mapping may contain some duplicated
strings which could waste a lot of memory.

3. Function mapping is good for generating URL according to the stations' code
names. However, if there are multiple rules, it might requires multiple if-else
branches.

My personal choice will be to combine the table mapping and function
mapping. This will be flexible enough to deal with different situations.