How to compare blank spaces in arrays?

Hello every one, I'm working on a little project on app designer where I need to do something like this:

Say I have two arrays of strings of the same size but the second has some 'blanks' as follows:

a=["red","blue","green","yellow"];

b=["orange","","","purple"];

How can I get a new array 'c' with the words from array 'a' that are at the same position as `blanks' in array 'b'?

the result would be:

c=["blue","green"];

Thanks for reading!

Answer 1

[Jonas]

use this

a=["red","blue","green","yellow"];
b=["orange","","","purple"];

c=a(b=="")

ans = 1×2 string array
    "blue"    "green"