how do I check if an object of an arraylist matches with another one no matter the order of the elements and their number of occurrences. let's say I have:
obj1 contains "boy", "girl", "kid"
obj2 contains "girl", "kid", "boy", "girl"
obj3 contains "woman", "boy", "girl", "kid"
all of arraylist
I want the program to achieve this:
obj1 = obj2 true
obj1 = obj3 false
obj2 = obj3 false
I think that you mean the following. You want to check whether unique elements contained in your lists are the same. The order does not matter.
To solve this problem you need set that contain only unique elements and do not preserve order:
List<String> first = ....
List<String> second = ....
boolean result = new HashSet<>(first).equals(new HashSet<>(second));
You should use containsAll() method:
List a = Arrays.asList("boy", "girl", "kid");
List b = Arrays.asList("girl", "kid", "boy", "girl");
List c = Arrays.asList("woman", "boy", "girl", "kid");
System.out.println(a.containsAll(b)); // true
System.out.println(a.containsAll(c)); // false
System.out.println(b.containsAll(c)); // false
Just to get you started, read about List .contains method. Use it in nested loops with boolean flag to indicate whether one list item satisfies .equals to any item in other list.
You will also need to decide whether comparison should be two way. You may have a scenario where all items of obj1 are present in obj2, but all items of obj2 are not present in obj1. In other words, obj2 is a superset of obj1.
Setthan aList.