推送未定义的属性

Question

有人可以为一个人提出“无法读取未定义的属性'推动”的光线，我的技能是有限的。

 function Position(position) {
      if (!position) {
        throw new Error('No position object given!');
      }
      this.lat = parseFloat(position.lat);
      this.lon = parseFloat(position.lon);

      this.timestamp = position.timestamp;
      this.heading = position.heading;
      this.speed = position.speed;
    };

    Position.prototype.getLatLng = function () {
      return new L.LatLng(this.lat, this.lon);
    };


    function Positions(positions) {
      if (!(positions instanceof Array)) {
        throw new Error('No positions array given!');
      }
      for (var i = 0; i < positions.length; i++) {
        this.positions.push(new Position(positions[i]));
      }
    };

Answer 1

this.positions 未在此功能中定义。尝试在推送操作之前定义它。

this.position = [];

Answer 2

尝试

for (var i = 0; i < positions.length; i++) {
        positions.push(new Position(positions[i]));
      }