Unique id consisting of only numbers

Question

I need to get time based unique id which would only consist of numbers, i was thinking to simply use something like this:

str_replace(".", "", microtime(true))

I would use this id for many things, for example comments posting, and i'm expecting quite high traffic so i would like to know how high are the chances of collision with microtime function?

And perhaps there is a better way to get numerical unique id? Just remember that it has to based on time so sorting could be done.

Answer 1

you can use this to get uniqid but is not numberic:

$id = uniqid(); //58aea16085f6b

use this to convert it to only numbers:

$id = hexdec( uniqid() ); //1560112880181100

if it's too long use this but maybe get negetive numbers:

$id = crc32( uniqid() ); //-1551585806

if you just need posetive numbers you can do it:

$id = abs( crc32( uniqid() ) ); //1551585806