Javascript lodash无法展平阵列

我正在尝试使用以下代码卸载当前使用的数组：

var mapped = _.flatMap(payload, ({GroupId,Learners}) =>
    _.map(Learners, LearnerId => ({GroupId:GroupId,Learner:LearnerId}))
);

但是，返回的值仍然生成和数组： e、 g

我如何调整上面的脚本以只返回GroupId和姓氏

有效载荷的示例如下所示：

var payload = 
{
    "GroupId": 1208864,
    "Code": "Ext-StuOth",
    "GroupType": "AcademicHouseGroup",
    "Learners": [
        {
            "LearnerId": 245218,
            "LearnerCode": "2009-0017",
            "Forename": "Sanelisiwe",
            "Surname": "Nazi-Angileh",
            "LearnerGroupLearnerId": 14719301,
            "StartDate": "2017-03-09",
            "EndDate": null
        },
        {
            "LearnerId": 246638,
            "LearnerCode": "2013-0076",
            "Forename": "Randal",
            "Surname": "Bodziarczyk",
            "LearnerGroupLearnerId": 14650361,
            "StartDate": "2017-02-20",
            "EndDate": null
        },
        {
            "LearnerId": 245253,
            "LearnerCode": "109056",
            "Forename": "Wafah",
            "Surname": "Dadisman",
            "LearnerGroupLearnerId": 14650360,
            "StartDate": "2017-02-20",
            "EndDate": null
        }
},{
            "GroupId": 1226419,
            "Code": "U6-JD",
            "GroupType": "RegistrationGroup",
            "Learners": [
                {
                    "LearnerId": 245507,
                    "LearnerCode": "110015",
                    "Forename": "Nahomy",
                    "Surname": "Osburn",
                    "LearnerGroupLearnerId": 14918706,
                    "StartDate": "2017-09-07",
                    "EndDate": "2018-07-31"
                },
                {
                    "LearnerId": 245994,
                    "LearnerCode": "111624",
                    "Forename": "Sherhona",
                    "Surname": "Dobritoiu",
                    "LearnerGroupLearnerId": 14707593,
                    "StartDate": "2017-08-01",
                    "EndDate": "2018-07-31"
                }
}

它不是数组，而是（包含数组的） 您可以按以下方式访问元素：

console.log（payload.GroupId）；
var学习者=有效载荷。学习者；
学习者。forEach（函数（学习者）{
console.log（学习者姓名）；

请修复问题的格式请添加一个（包括输入和预期输出）来显示实际问题。您的有效负载是什么？我添加了有效负载示例Hopping playload=[…yourgiven json]这会产生一个缺失值。缺失了什么

var payload = 
{
    "GroupId": 1208864,
    "Code": "Ext-StuOth",
    "GroupType": "AcademicHouseGroup",
    "Learners": [
        {
            "LearnerId": 245218,
            "LearnerCode": "2009-0017",
            "Forename": "Sanelisiwe",
            "Surname": "Nazi-Angileh",
            "LearnerGroupLearnerId": 14719301,
            "StartDate": "2017-03-09",
            "EndDate": null
        },
        {
            "LearnerId": 246638,
            "LearnerCode": "2013-0076",
            "Forename": "Randal",
            "Surname": "Bodziarczyk",
            "LearnerGroupLearnerId": 14650361,
            "StartDate": "2017-02-20",
            "EndDate": null
        },
        {
            "LearnerId": 245253,
            "LearnerCode": "109056",
            "Forename": "Wafah",
            "Surname": "Dadisman",
            "LearnerGroupLearnerId": 14650360,
            "StartDate": "2017-02-20",
            "EndDate": null
        }
},{
            "GroupId": 1226419,
            "Code": "U6-JD",
            "GroupType": "RegistrationGroup",
            "Learners": [
                {
                    "LearnerId": 245507,
                    "LearnerCode": "110015",
                    "Forename": "Nahomy",
                    "Surname": "Osburn",
                    "LearnerGroupLearnerId": 14918706,
                    "StartDate": "2017-09-07",
                    "EndDate": "2018-07-31"
                },
                {
                    "LearnerId": 245994,
                    "LearnerCode": "111624",
                    "Forename": "Sherhona",
                    "Surname": "Dobritoiu",
                    "LearnerGroupLearnerId": 14707593,
                    "StartDate": "2017-08-01",
                    "EndDate": "2018-07-31"
                }
}

var result = _.flatMap(payload, ({GroupId, Learners}) => {
    return _.map(Learners, learner => ({GroupId, LearnerId: learner.LearnerId}))
})