Why someone would use a hexadecimal approach in javascript?

I apologize cause this may be a bizarre question but I'm pretty confused. Would anyone know why someone would use what I believe to be "a hexadecimal approach" to javascript? i.e.) I see someone naming variables like

_0x2f8b, _0xcb6545,_0x893751, _0x1d2177, etc

Why would anyone ever do this? Also, I see code like

'to\x20bypass\x20this\x20link' 

as well as hexadecimals for numbers such as 725392

0xb1190

So, how would anyone even get this kind of naming convention and why would they ever want to use this?