Intersection() method

[Raimon]

I have the same question as Jack007 at page:

Array.intersect solution

public Array intersect(Array other) { var intersection = new Array(count); for (int item : items) if (other.indexOf(item) >= 0) intersection.insert(item); return intersection; } Can someone please explain the second line? (Or the logic of the entire method itself cuz I don’t get it) The method is supposed to return elements common between two Arrays, however I don’t understand why that line gives the intended result. Doesn’t that line just check to see if the index is greater than or …

There was a solution given but I don’t understand. Can someone explain it to me?

This was part of the exercizes in the Arrays module lesson 10:

https://codewithmosh.com/courses/639884/lectures/11425328

Lesson-question:

Extend the Array class and add a method to return the common items in this array and another array.

My question:

How do I use the intersection() method in the Array.

I have attached two screenshots to show my code.

Best,

Raimon

[jmrunkle]

You need to save the Array returned by the intersect method into a variable and then print that. Also, the intersect operation is really only useful with two different arrays.

For example:

// ... setup numbers with 1..7
Array otherNumbers = new Array(3);
otherNumbers.insert(1);
otherNumbers.insert(5);
otherNumbers.insert(10);
Array intersection = numbers.intersect(otherNumbers);
intersection.print(); // should have 1 and 5

[Raimon]

Thank a lot jmrunkle, I’m going to try your explanation later. Just wanted to respond to show my appreciation.

[Raimon]

Thanks again Jason, it worked