Looping a triangle

I felt like my grasp of loops wasn't good enough to complete the excercise I was given in Session 3 with Richard. I started to attempt the excercises in Eloquent Javascript to supplement my learning and get a better grasp on how to write the logic that was being asked of me.

Here's the first task:

Write a loop that makes seven calls to console.log to output the following triangle:

#
##
###
####
#####
######
#######

My solution:

let hash = '#'
let counter = 0
let prev = hash
while (counter <= 7) {
  console.log(hash)
  hash = hash + prev
  counter = counter + 1
}

I thought this was really similar to the fibonnacci problem I was given in Session 1, only this time I think I finally understood how to write operations like this myself:

counter = counter + 1

I think I would call this a very small but fun breakthrough.

I now fully understand these lines of code:

let counter = 0

while (counter <= 7)

counter = counter + 1

I understand that I can create a counter that has a value of zero and then manipulate it inside of a loop.

On this task I did not have to google, search or lean on any material other than that in the book. This felt like an enormous achievement given that I easily give up on finding the solution myself and start furiously googling.