JavaScript: parseInt(string, 36) converts different strings to same number

Question

I have an issue with string conversion:

When using parseInt(string[,radix]) like so:

BigInt(parseInt('something', 36))

it outputs: 80920602611116n. with a different input like so:

BigInt(parseInt('somethink', 36))

it outputs: 80920602611120n, which is something else of course.

However if it's a longer string, the output number is the same sometimes:

BigInt(parseInt('thisisactuallyadifferentsomething', 36))
BigInt(parseInt('thisisactuallyadifferentsomethink', 36))

this would output 1867697451648055638757226289961051507749359223570432n for both, although they are different.

I know, that there is a limit for safe representation of integers, that's why I used BigInt, which has no limit.

I have to be able to differ strings of this size, while using BigInt to represent those.

For some reason the Javascript BigInt type is relatively crippled compared to every other bigint type in the world. — President James K. Polk
– President James K. Polk, Commented Apr 20, 2020 at 16:09

Trentium · Accepted Answer · 2020-05-18 21:17:09Z

2

See encode a big integer to base62, but replace the following base 62 digits...

var digits = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';

...with the base 36 digits...

var digits = '0123456789abcdefghijklmnopqrstuvwxyz';

Hope this helps...

answered May 18, 2020 at 21:17

Trentium

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