Filling an image with JS

I’ve got an ASCII pic like this one: The pic is an array and each line is a data set of the array. I want to replace all the semicolons with dots but only those INSIDE the Smiley. I want to write a function but indexOf or splicing that array doesn’t really help … any hint would be much appreciated!

I can’t understand a single thing you’re trying to say here, could you elaborate a little more on what lesson you’re on, add your code, and any other information to make this easier for us to help you would make this go much more smoothly.

Oops, typed a reply while the misses was still logged in!

My question is not about a lesson and I’ve got no code since I don’t know which function(s) to use for this. I’m afraid I don’t know how to explain it better - the ASCII pic is an array and I want to replace all the characters inside the boundaries of the smiley face with another character, let’s say asterisks.

So you want to modify that image using Js ?