function copyWoorld(str) {  var arr = str.split('');  var newArr = [];  var arr2 = [];  arr.forEach(function (ele,index,arr) {  if( ele == '，' || ele == '。') {   }else {  if(newArr.indexOf(ele)<0){  newArr.push(ele);  }else{  arr2.push(ele+ele);  }  }  });  return arr2;  }  console.log(copyWoorld('独坐常忽忽，情怀何悠悠。山腰云缦缦，谷口风飕飕。'));