<分区>
给定以下成员数据数组，我将为成员资格状态不是最新的成员返回一组 memberID。
这是成员数据:
var members = [
{
firstName: 'Howard',
lastName: 'Lee',
membershipIsCurrent: true,
MemberID: 235
},
{
firstName: 'James',
lastName: 'Icharis',
membershipIsCurrent: false,
MemberID: 236
},
{
firstName: 'Thomas',
lastName: 'Cronquist',
membershipIsCurrent: true,
MemberID: 237
},
{
firstName: 'Philip',
lastName: 'Grover',
membershipIsCurrent: false,
MemberID: 238
},
{
firstName: 'Eric',
lastName: 'Broadstone',
membershipIsCurrent: true,
MemberID: 239
},
{
firstName: 'Hunter',
lastName: 'Gonzales',
membershipIsCurrent: true,
MemberID: 240
}];这是我获取该数据的代码:
function lapsedIDs (array ) {
return array.map( function ( member ) {
if ( member.membershipIsCurrent === false ) {
return member.MemberID;
}
});
}
lapsedIDs(members);这是结果。我不明白为什么它会为每个成员资格尚未失效的成员返回 undefined。有什么指点吗？？
[ undefined, 236, undefined, 238, undefined, undefined ]