giving a unique random number for user identification

[rohitchawla]

The only way i know is either using combinations like

var a=Math.round(Math.random()*1000000);
var b=Math.round(Math.random()*1000000);
var c=Math.round(new Date().getTime()/1000);
 
d=a+""+b;
e=a+""+c;
 

is there any other way to get a unique number with a very low probability of them being same

[gits]

hi ...

the following should always generate a unique value:

var unique_val = + new Date;

kind regards

[rohitchawla]

thanks gits

but its in my code

var c=Math.round(new Date().getTime()/1000);
 

[gits]

not exactly as you can see :) ... you kill the last 3 positions with dividing by 1000 and round the result ... that gives the chance to be not unique when its called too fast ... try it ;)

[rohitchawla]

i know it gives result in milliseconds

but i want a different type of random number that is not math.random or new date

is there any other type of random number

[gits]

hmmm ... i don't know ... to be sure the timestamp is always unique ... even a random number might have a chance not to be unique ... but in case you want to have a 'pool' of numbers then you may create a list with numbers that you may assign to a user each time ... and assign that only once ...

[rohitchawla]

thanks gits
ill try then combination of math.random and date object
i was checking if another type of random number exists

[gits]

can you tell the purpose of this? it's better to assign a number at the server i think ... because it is (might be) security relevant? ...

[rohitchawla]

nope it is nothing security relevant
i am using this for behavioral targeting
if i get a unique visitor number i might be able to track them
and with so many request on server engine i cant use it to set a unique number every time a visitor visit the websites as it will increase the load

[gits]

i see ... so you assign the id to the user and track his behaviour with this id and may be he is getting proposals or special links or interfaces depending on his behaviour? :) ...

good luck with your project ... and post back to the forum anytime you have more questions,

kind regards