Human readable numbers [duplicate]

Question

Is there an easy way and dynamic way to format numbers in a string to be human readable? For example turn 10000000000 into 10,000,000,000. I have seen this question but the answers are outdated and broken (the one with the example).

Answer 1

Try this psuedo algorithm:

1. Divide the string length by 3
2. Round that down, and we'll call it x

3. Loop over the string x times, going backwards:

   1. Get the string at x times 3 position, or index [(x times 3) - 1], we'll call it y.
   2. Replace y with "," + y