Bizarre Array Behavior

[jacmac 2]

So I'm trying to build an array of positions. I start with a marker position and use set commands to alter the position in an array variable. I then add the position to an array of positions:

_originpos = getMarkerPos _marker;
_pos = _originpos;
diag_log  ("wp _pos " + str _pos);
_pos set [0,((_originpos select 0)+25)];
diag_log  ("wp _pos " + str _pos);
_pos set [1,((_originpos select 1)-25)];
diag_log  ("wp _pos " + str _pos);
_wppos = [_pos];
diag_log  ("wp _wppos " + str _wppos);
_pos set [0,((_originpos select 0)+25)];
diag_log  ("wp _pos " + str _pos);
_pos set [1,((_originpos select 1)+30)];
diag_log  ("wp _pos " + str _pos);
_wppos = _wppos + [_pos];
diag_log  ("wp _wppos " + str _wppos);
_pos set [0,((_originpos select 0)-30)];
diag_log  ("wp _pos " + str _pos);
_pos set [1,((_originpos select 1)+30)];
diag_log  ("wp _pos " + str _pos);
_wppos = _wppos + [_pos];
diag_log  ("wp _wppos " + str _wppos);
_pos set [0,((_originpos select 0)-30)];
diag_log  ("wp _pos " + str _pos);
_pos set [1,((_originpos select 1)-30)];
diag_log  ("wp _pos " + str _pos);
_wppos = _wppos + [_pos];
diag_log  ("wp _wppos " + str _wppos);

The code above produces some rather bizarre results:

"   _pos [5344.89,5240.91,0]" Origin
"   _pos [5369.89,5240.91,0]" Element 0 altered
"   _pos [5369.89,5215.91,0]" Element 1 altered
"_wppos [[5369.89,5215.91,0]]" _pos added to _wppos
"   _pos [5394.89,5215.91,0]" Element 0 altered
"   _pos [5394.89,5245.91,0]" Element 1 altered
"_wppos [[5394.89,5245.91,0],[5394.89,5245.91,0]]" _pos added to _wppos, but wait! WTF???!?!? What happened to [5369.89,5215.91,0]???
"   _pos [5364.89,5245.91,0]" Element 0 altered
"   _pos [5364.89,5275.91,0]" Element 1 altered
"_wppos [[5364.89,5275.91,0],[5364.89,5275.91,0],[5364.89,5275.91,0]]" WHAT???
"   _pos [5334.89,5275.91,0]" Element 0 altered
"   _pos [5334.89,5245.91,0]" Element 1 altered
"_wppos [[5334.89,5245.91,0],[5334.89,5245.91,0],[5334.89,5245.91,0],[5334.89,5245.91,0]]" OMG FAIL!

Why do all of the elements in _wppos get overwritten when _pos is added to the array? It is like _wppos = _wppos + [_pos]; means add [_pos] as a new element to the array and copy it into every existing element in the array.

[ceeeb 147]

Biki entry on Array data types

Note that arrays are treated in a similar way to objects - the variable points to the data, so declaring an array containing another array does not copy the original array, just references it.

This means that changing _pos after _wppos = [_pos], will affect _wppos.

[killzone_kid 1326]

What ceeeb said. Just change

_pos = _originpos;

to

_pos = +_originpos;

If you need more info on arrays http://killzonekid.com/arma-scripting-tutorials-arrays-part-1/

[jacmac 2]

Biki entry on Array data types

Note that arrays are treated in a similar way to objects - the variable points to the data, so declaring an array containing another array does not copy the original array, just references it.

This means that changing _pos after _wppos = [_pos], will affect _wppos.

That does explain the behavior. Nutty as it seems, this function manages to dereference the array elements and add an array into an array:

_func_AddArrayIntoArray =
{
_temp = [];
_addlength = count (_this select 1);
for "_i" from 0 to (_addlength - 1) do
{
	_temp set [_i, ((_this select 1) select _i)]
};
_return = ((_this select 0) + [_temp]);
_return
};

I have to say though, this array behavior is pretty much mentally bankrupt!

[killzone_kid 1326]

what mentally bankrupt is the example function above since you can just add arrays a = a + with no consequence it is set function you have to be careful with

[jacmac 2]

what mentally bankrupt is the example function above since you can just add arrays a = a + with no consequence it is set function you have to be careful with

Sorry, I can't understand what you're trying to say; your sentence has no breaks in it.