cc.Class({
    extends: cc.Component,

    properties: {

        flags: {
          default: [],
          type: [cc.Node],
        },
        speed: 2,
        _currentMove: 0,
        _forward: true,
    },

    // use this for initialization
    onLoad: function () {

    },

    start: function () {
        this.node.position = this.flags[0].position;

    },
    // called every frame, uncomment this function to activate update callback
    update: function (dt) {
         this.movement();
    },

        movement: function () {
// comparePos is a custome helper method, check bottom of script
            if (this.comparePos(this.node.position,  this.flags[this._currentMove].position)
            && this._forward) {
                this._currentMove++;
                this.moveActions();

        }
        else if (this.comparePos(this.node.position, this.flags[this._currentMove].position)
        && !this._forward) {
            this._currentMove--;
            this.moveActions();
        }  

        if (this._currentMove >= this.flags.length - 1) {
            this._currentMove = this.flags.length - 1;
            this._forward = !this._forward;
        }
        else if (this._currentMove <= 0) {
            this._currentMove = 0;
            this._forward = !this._forward;
        }
    },

    moveActions: function () {
        var move = cc.moveTo(this.speed, this.flags[this._currentMove].position);
        this.node.runAction(move);
    },

    comparePos: function (a, b) {
        return Math.round(a.x) == Math.round(b.x) && 
        Math.round(a.y) == Math.round(b.y)
    },

});

I'm using Cocos Creator, basically I have an array of empty objects, and I want my enemy to patrol back and forth towards those objects. The problem is the enemy would complete a full round ( move towards all objects and back) and then gives me error when it goes back to the first object, strangely enough, sometimes it will complete more than 1 round before giving the error:

Uncaught TypeError: Cannot read property 'position' of undefined

It might be because the position comparison is not accurate enough, but I don't know how else to do it.