How to find a value of a vector from another one?

There are two (A&B) vectors with N samples each. Each number of A has a specific value in B.

I have a value in A (a number among N samples), and interested to find it in B. For example:

A=[250 400 300 200 100 ...]

B=[5 6 1 2 9 ...]

I want to find B when A =200, the answer is B=2 (in this case).

Thanks

Answer 1

[Ingrid]

is this what you mean?

B(A==200)

[Amin Ganjavi]

I thought it is much more complex and need to use arrayfun.

Thank you