If you simply define A and B, you could use it in JavaScript immediately:
var A, B
var array = [[A,150,500,6000],[B,160,700,7000],[B,200,633,9000],[B,210,633,9000]]
var second = array[1];
var element = array[1][1];
Alternatively, you can parse string, and so on, but you can simply use it as the argument of the call to
eval
and do all of the above.
—SA