Weird sorting behavior in AS

Question

Consider the code:
var a:Array = new Array();
a.push({str:"a", val:2});
a.push({str:"b", val:3});
a.push({str:"c", val:2});
a.push({str:"d", val:2});
a.push({str:"e", val:3});
a.sortOn("val", 16);
for (var i:int=0; i<=4; i++){
trace(a
.str + " -- " + a.val);
It outputs:
c -- 2
d -- 2
a -- 2
b -- 3
e -- 3
Why does it change the original order - shouldn't the output
be a,c,d,b,e - whereas the output is c,d,a,b,e? I tried it in both
AVM1 and AVM2.
Any clues would be greatly appreciated.
Thanks,
Pallav

Answer 1

i don't think you can guarantee the order of sorted elements
where the field you're sorting on is equal. for example, if you
sortOn val again, the order changes again:
a -- 2
d -- 2
c -- 2
b -- 3
e -- 3
if you need it to retain original sort order where sort
fields are equal you may have to write that sort routine yourself.
alternatively, if it helps you could sort on two fields: