truncateStr.js

function truncateStr(str, num) {
  
  if(str.length > num)
  {
    if(num > 3)
    {
      str = str.slice(0,num-3)+"...";
    }
    else
    {
      str = str.slice(0,num)+"...";
    }
  }
  
  
  return(str);
}

truncateStr("Peter Piper picked a peck of pickled peppers", 14);