Question

I’m building a javascript - html5 canvas side-scroller game. The terrain consists basically on a double-entry table like this one:

      -1   2   10  
-----------------
0     b    a    c
-----------------
2     a    b    a
-----------------
5     a    a    b
-----------------

(the columns and rows represent the position on the map and a, b and c would state what’s on that space).

I don’t know how to save this table so I can retrieve any range of it quickly later on. I can’t think of any terminology that helps me search for the solution either, so any info and help tagging the question will be of help.

Answer 1

Use JSON for saving such data:

var map = {
    '0': {
        '-1': 'b',
        '2': 'a',
        '10': 'c'
    },
    '2': {
        '-1': 'a',
        '2': 'b',
        '10': 'a'
    },
    '5': {
        '-1': 'a',
        '2': 'a',
        '10': 'b'
    }
};

And retrieve your data like that: map['2']['-1'].

You can also change it like that also map['2']['-1'] = 'c'.

Some function for easier manipulation of this object could be written by you if you like.