Javascript Function Creation Question 2

let items = new Array('apple','orange','cherry','lime');
let sep = '*';
concatenateString(items,sep);/*from   ww  w. j  av  a 2 s  .  c  o  m*/

console.log(items);

function concatenateString(strings, separator) {
  let result="";
  for (let i = 0; i < strings.length; i++) {
    result+=strings[i] + separator;
  }

  // assign result to separator
  separator = result;

  // and array
  strings[strings.length]=result;
}