数组转字符串

  //数组转字符串
    arrToStr( objarr ){
      var arrLen = objarr.length;
      var row = "[";
      for (var i = 0 ;i < arrLen ; i++){
        row += "[";
        for(var j = 0; j < objarr[i].length; j++){
          row += objarr[i][j];
          if(j < objarr[i].length-1){
            row +=",";
          }
        }
        row += "]";
        if(i<arrLen-1){
          row+=",";
        }
      }
      row+="]";
      return row;
    },

转换效果：
[[116.29413671875,39.98160461425781],[116.29413671875,39.98160461425781],[116.43283911132812,39.87448791503906]]