无法访问我的数组映射中的对象属性？

Question

我无法从我的阵列中访问对象的属性。

这是我的代码：

{
    this.props.viewer.messagesByUser.edges.map(edge => {
        console.log("chatFriendPopPup id = ", chatFriendPopPup.id)
        console.log("receiver['_id'] = ", edge.node.receiver['_id']) // returns undefined
        console.log("receiver._id = ", edge.node.receiver._id) // returns undefined
        console.log("receiver._id = ", edge.node.receiver)
        if (edge.node.receiver._id.toString() === chatFriendPopPup.id.toString()) {
            return <li > {
                edge.node.body
            } - seen: {
                edge.node.seen
            } < /li>
        }
    })
}

Receiver有这样的属性，但我无法获得._id

{
    _id: 597 f7eb1e5131d5a50e18d14,
    updatedAt: 2017 - 07 - 31 T19: 02: 09.035 Z,
    createdAt: 2017 - 07 - 31 T19: 02: 09.035 Z,
    fullName: 'ria atayde',
    email: 'myloves@gmail.com',
}