for and if loops question

I'm having a really hard time wrapping my head around how to do this problem, I'm not asking for a direct answer just a step in the right direction. I understand I need to use a for loop to scan through each value of the vector but I don't know how to make it realize if theres also a number just like it in the other two. Heres the question:

This function takes in three different Vectors. Use for loops to scan through the Vectors and copy any value that appears in all three Vectors into a result. You will need 3 for loops for this function.

Can someone help?

[Azzi Abdelmalek]

What are you looking for in these vectors?

Answer 1

[Ingrid Tigges]

Is there a reason you are supposed to use 3 for loops? A hint: Have a look at the function INTERSECT. Using this function the task can be done in 2 lines of code without the use of any loop.

Answer 2

[William]

Thats required by the assignment I believe, but I'll look into the intersect function.

[Ingrid Tigges]

Good luck with your homework.

Answer 3

[Image Analyst]

You're required by the directions to use loops so you'll need something like 3 pairs of double for loops (to compare all 3 possible pairs of vectors) with something like this inside each pair of for loops

if oneVector(j) == theOtherVector(k)
  savedNumbers(count) =

okay, that's enough of a hint. Actually you can do it with one set of 3 nested for loops (like they asked you to), but additional if statements, if you're a little more clever about it.