Re: How to: referencing variables using the contents of otehr
variables.
On Apr 14, 10:27 pm, Mark Space <marksp...@sbc.global.net> wrote:
fguy...@gmail.com wrote:
For example, the char variable named P can have the value 'K', and
there is also a two dimensional array named K[][] of type String.
Yes and no. First, you can't have two variables declared in the same
scope with the same name;
char k;
int[][] k; // error
won't compile. You must give them different names.
The easiest way to accomplish what you want is probably to just make
your own type.
class CharData {
char k;
int[][] data;
}
Now you have bound a char and a two dimensional array 'data' together.
You don't need a switch or any look up to access one from the other.
There might be better ways to do this. I've provided no getters or
setters, the variables are not private, and there's no constructor.
Depending on your application, it might be better to add some of those,
or to do something different altogether. If you post some more detail
of what you are actually trying to do, we might be able to help you more.
Thanks to Mark, and everyone else who replied.
OK here is the situation...
I am trying to simulate pieces on a chess board. I am well into the
project and don't really want to redesign my data structures. My
question is not really a showstopper, it's really just an academic
question. it would just make the code a little neater.
OK, my chessboard is represented by an 8x8 char array, call it posn[]
[]. each cell contains one char, which corresponds to FEN notation. an
empty square is '1'. A White King is 'K", a black king is 'k', and so
on.
ok for each char value in the posn array there corresponds an 8x8
static final array of strings. consider the array K[][]. K[i][j]
contains a string made up of pairs which are the row and column co-
ordinates of all the squares on an empty chessboard a white King can
move to when it starts on the square i j.
In my program, a move is described by a starting an ending pair. In
having the program build a list of legal moves, I start by examining
each cell in the position array, looking for either uppercase or
lowercase letters depending on if it is white's turn or black's turn.
so if posn[i][j] contains 'K', I wish to reference the string K[i][j].
As it stands, I do it as follows...
for( int i =0; i<8; i++ ) {
for(j=0; j<8; j++) {
if( posn[i][j] !='1') {
String destinations = getDests( posn[i][j], i, j );
// process destinations
}
}
}
String getDests( char piece, int row, int col ) {
switch( piece ) {
case 'K': return K[row][col];
..
case 'n' :
case 'N': return n[row][col]
..
..
..
}
etc etc.
OK the select statement is not bad, and I want to keep the data
structure simple. It is more of an academic question really. Is there
some kind of built in JAVA reference function which would eliminate
the need for a switch statement?