Please tell me how to declare a String variable to be used to append 8 unique random numbers?

Do you mean you have a string and want to add 8 characters TO the existing string?Or, do you have an array and want to add elements to the array, each with a set of 8 random numbers? Let's go for appending 8 random number characters as that is easier to run through than the array...

s$=""

a$="0123456789"

randomize 'initialize the random number generator

x = 0

for y=1 to 8

x=random(len(a$)) 'select a random number from 0 to length of a$

a$=s$=s$+substr(a$,x,1) ' append the number character

next y

print s$ ' print the 8 character number string

-=+=-

Is this the kind of thing you wish to do? Note that in this example, single digits CAN repeat within the string.

Two ways to define string in c language. 1) character array char name[20]; 2) pointer of character char name*;

you should specify the programming language u r using c++, Java, so on