[ivanhoe]

If you have int(percent * 10) + 1 you can just generate that many blue circles (checking for the edge-case of zero, or even better using ceil instead of int), the rest white and return it - no need for manually crafting the array (since the performance is, I presume, not a critical thing here). If tomorrow you want stars instead of the circles you just edit 2 chars in one place, instead of typing manually all combinations.

[kwhitefoot]

The compile time allocated array is to avoid allocations at run time, if that is a requirement. In a language with proper macros such as Nim or Lisp this can be done at compile time using exactly your approach. That way it executes fast and is just as simple .

[ivanhoe]

I've been looking into nim lately (just for fun with the Advent of Code problems) and it looks fantastic. I plan to allocate more time to it in future definitely.

[dayvan]

Find-and-replace exists.

Having a separate string for each level of progress also lets you do other kinds of customizations: you could have a rainbow progress bar, or put little bits of encouraging text to the right of the progress bar, like "Almost there!" at 90%.

Essentially, you're making one type of customization (i.e., changing the symbols) slightly easier, at the expense of making other types of customization harder.