How to create unique ID which never repeats again?

[Saksham_Goyal]

No problem …You are too helpful

[Alapjeet (Alapjeet Singh)]

Ya yo can do with that also…

[Saksham_Goyal]

How to do that please help me in doing that.I also need blocks for this.

[vknow360 (Sunny Gupta)]

In one of my project I use this to generate a unique user id for each user:

Maybe this can be useful.