我不能得到用户和朋友的出生年份（javascript sdk，fb api）

Question

我想要过生日年来计算年龄但是生日。年纪给我未定义。

有没有其他方法可以获得用户和朋友的年龄（不是age_range）或获得生日年份？

这是我的代码。

    function testAPI(){
        FB.api('/me?fields=name,email,birthday,location,age_range',function(response){
            if(response && !response.error){
                console.log(response);
                buildProfile(response);
            }

        FB.api('me/friends?fields=id,name,gender,first_name,birthday,location',function(response){
                if(response && !response.error){
                    console.log(response);
                    buildfriends(response);
            }
              }
            );

    }
    //user info
    function buildProfile(user){
        let profile=`
            <h3>${user.name}</h3>
            <ul class="list-group">
                <li class="list-group-item">User Id: ${user.id}</li>
                <li class="list-group-item">Email: ${user.email}</li>
                <li class="list-group-item" >Birthday: ${user.birthday.year}</li>
                <li class="list-group-item onload">User Location: ${user.location.name}</li>
            </ul>
        `;
            document.getElementById('profile').innerHTML = profile;
    }

    //friends info
    function buildfriends(friends){
        let friendlist='<h3>Friend List</h3>';
        for(let i in friends.data){
                friendlist +=`
                    <div class ="well">
                        ${friends.data[i].name} <br>
                        ${friends.data[i].id} <br>
                        ${friends.data[i].first_name} <br>
                        ${friends.data[i].gender} <br>
                        ${friends.data[i].birthday} <br>

                    </div>
                `;
        }
        document.getElementById('friends').innerHTML=friendlist;
    }
    }