Junit assertCollection?

What's the best way to unit test that 2 collections are the same.
(Not the same object, but each element value of one collection is in the other, and vice versa)
LVL 1
allelopathAsked:
Who is Participating?
 
for_yanConnect With a Mentor Commented:

I think this should work even if each collection
has identical items:

boolean areTheyEqual(ArrayList a1, ArrayList a2){
if(a1.size() != a2.size() ) return false;
for(int j =0; j<a1.size(); j++){
int count1 = 0;
for(int k=0; k<a1.size(); k++){
if(a1.get(j).equals(a1.get(k))count1++;

}
int count2 = 0;
for(int k=0; k<a2.size(); k++){
if(a1.get(j).equals(a2.get(k))count2++;

}
if(count1 != count2)return false;

}
retrurn true;

}
0
 
for_yanCommented:

Are all objects in your collections unique?
Or you may have two equal options present in any of your two collections?

if they are unique then if the sizes of both collections are equal,
and then you just traverse one collection and check that
all elements of this coll;ection are present in the second collection then
tyour collections are the same in the sense you mentioned
0
 
for_yanCommented:

if my question above has the anser "yes" then this method should work:

boolean areTheyEqual(ArrayList a1, ArrayList a2){
if(a1.size() != a2.size() ) return false;

for(int j=0; j<a1.size(); j++){
if(!a2.contains(a1.get(j)){
return false;
}
}
return true;

}

0
Keep up with what's happening at Experts Exchange!

Sign up to receive Decoded, a new monthly digest with product updates, feature release info, continuing education opportunities, and more.

 
allelopathAuthor Commented:
Thanks.
Looks like I could also use Apache Commons CollectionsUtils
CollectionUtils.isEqualCollection(actual, expected);
0
 
for_yanCommented:
Yes, you are right - that probably would be better.
But it is nice to invent the wheel also :)
0
 
CEHJCommented:
coll1.removeAll(coll2);
boolean identical = coll1.size() == 0;
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.