Javascript: toString(36) for large integers

Question

15955067621307336078.toString(36); returns '3d7vzfy5k2as8' in Javascript because the large integer cannot be represented (the correct answer is '3d7vzfy5k29ou').

Does someone have a clever function that takes a large integer as a string and converts it to base 36?

Actually, I get `"3d7vzfy5k2a68"` for `15955067621307336078..toString(36)` — Bergi, Nov 26 '12 at 21:53
I tried writing my own base conversion function, but it stops working completely after a certain size. http://jsfiddle.net/SEZXq/1/ — HellaMad, Nov 26 '12 at 22:08
@Bergi - The largest int that JavaScript supports is 9007199254740992. You're number is over that, so the answer you get is determined by how the implementation misbehave when there is overflow. See [this thread](http://stackoverflow.com/a/307200/535871). — Ted Hopp, Nov 26 '12 at 22:21

score 9 · Accepted Answer · answered Nov 26 '12 at 21:53

9

Use this BigInt class, which allows conversion of arbitrarily large integers to any arbitrary base between 2 and 95. Use the bigInt2str() method to perform the conversion.

answered Nov 26 '12 at 21:53

Robert Harvey

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Thanks this worked great. `bigInt2str(str2bigInt("15955067621307336078",10,0,0),36).toLowerCase();` – Meekohi Nov 26 '12 at 23:36

score 1 · Answer 2 · answered Apr 07 '16 at 03:06

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For anyone curious, today we are using https://github.com/MikeMcl/bignumber.js instead.

answered Apr 07 '16 at 03:06

Meekohi

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Javascript: toString(36) for large integers

2 Answers2