javascript map函数返回

Question

我需要将所有参与者的idNumber分配给idNumbers。你能检查一下我的代码吗？

const participants = [
  { name: 'Abu', idNumber: 'S7282395H', gender: 'male' },
  { name: 'Mary', idNumber: 'T4689018Z', gender: 'female' },
  { name: 'Suzi', idNumber: 'G5512873T', gender: 'female' },
  { name: 'T Chakra', idNumber: 'T8198514B', gender: 'male' }
];
// pass a function to map
const getIds= participants.map((name) => `${participants.name} ${participants.idNumber}`);
console.log(getIds);

Answer 1

您应该在map中引用name，而不是participants

​

const participants = [
  { name: 'Abu', idNumber: 'S7282395H', gender: 'male' },
  { name: 'Mary', idNumber: 'T4689018Z', gender: 'female' },
  { name: 'Suzi', idNumber: 'G5512873T', gender: 'female' },
  { name: 'T Chakra', idNumber: 'T8198514B', gender: 'male' }
];
// pass a function to map
const getIds= participants.map((name) => `${name.name} ${name.idNumber}`);
console.log(getIds);

​

Answer 2

如果您只想要一个idNumber数组，那么可以像这样使用map

​

const participants = [
{ name: 'Abu', idNumber: 'S7282395H', gender: 'male' },
{ name: 'Mary', idNumber: 'T4689018Z', gender: 'female' },
{ name: 'Suzi', idNumber: 'G5512873T', gender: 'female' },
{ name: 'T Chakra', idNumber: 'T8198514B', gender: 'male' }];

const getIds = participants.map(participant =>  participant.idNumber);

console.log(getIds);

​

如果需要包含名称和idNumber的字符串数组，可以使用字符串插值。

​

const participants = [
{ name: 'Abu', idNumber: 'S7282395H', gender: 'male' },
{ name: 'Mary', idNumber: 'T4689018Z', gender: 'female' },
{ name: 'Suzi', idNumber: 'G5512873T', gender: 'female' },
{ name: 'T Chakra', idNumber: 'T8198514B', gender: 'male' }];

const getIds = participants.map(participant =>  `${participant.name} ${participant.idNumber}`);

console.log(getIds);

​

Answer 3

在这段代码中

const getIds= participants.map((name) => `${participants.name} ${participants.idNumber}`);

您需要引用name参数，而不是参与者。这需要

const getIds= participants.map((name) => `${name.name} ${name.idNumber}`);

我建议将name参数更改为更明确的内容，因为name.name本身并不是很干净……