How to correctly compose a link from a js array?

Question

Arrays

Let's say we have an array:
var array = [1,2,3,4,5,6,...,999];
How to correctly compose such a link, from the first 500 array values:
https://test.ru?test=1 ,2,3,4,5,6,...500
Do not write https://test.ru?test =array[0] ,array[1]
I understand what is needed through the loop, but I don't understand how exactly.
Thank you for your attention.

Answer 1

var arr = [ 1, 2, 5, 10, 20, /* ещё куча элементов */ 999 ];
var url = 'http://example.org/?test=' + arr.slice( 0, 500 ).join( ',' );