Back to math

[SeanGrebey]

It's probably not the best way, but if I was going to do it, I'd create an object that represents an expression, and attach an ArrayList or a linked list to it or something that represented each part of the expression as the same type of object, and so on until the expression was broken down to the lowest elements, and I'd sort the list by order of operations. Then when I was evaluating the expression, I'd start of with the first child object, and follow the children all the way down to the lowest level, do all those operations, then float up to the next level, 2nd object, and follow the tree down again.

So: 4 + (5 * 7) / 3

MasterObject.Expression = "4 + (5 * 7) / 3"
MasterObject.SubExpressions(0) = (5 * 7)
MasterObject.SubExpressions(1) = MasterObject.SubExpressions(0) / 3
MasterObject.SubExpressions(2) = MasterObject.SubExpressions(0) + 4

Or a More complex:

10 * (7 + 4 / 2) - 13

MasterObject.Expression = "10 * (7 + 4 / 2) - 13"
MasterObject.SubExpressions(0) = (7 + 4 / 2)
MasterObject.SubExpressions(0).SubExpressions(0) = 4 / 2
MasterObject.SubExpressions(0).SubExpressions(1) = MasterObject.SubExpressions(0).SubExpressions(0) + 7
MasterObject.SubExpressions(0) = MasterObject.SubExpressions(1) * 10
MasterObject.SubExpressions(0) = MasterObject.SubExpressions(2) - 13

So basically you just order your children by mathimatical order of operation, and then run down the tree. So we start at child Object 0.

Object 0 - > Have children? Yes, Go down one
Object 0, Object 0 -> Have Children, No? Evaluate:
Object 0, Object 0 = 2
Any other elements in this array? Yes
Object 0, Object 1 = 9
Any other elements in this array? No
So
Object 0 = 9
Any other elements in this array? Yes
Object 1 = 90
Any other elements in this array? Yes
Object 2 = 77
Any other elements in this array? No

Expression = 77

[Lord_Rat]

[...]

Not to be mean (certainly not).

But that seems like quite the headache. I hurt even thinking about it ><

[SeanGrebey]

Heh, I didn't say it was the best way, but it would work and the coding would be pretty easy. Flow down to lowest level child, do math across, pop answer up.