Question

var students = ["Malcom", "Jayne"];
var persons = [
    {firstname : "Malcom", lastname: "Reynolds"},
    {firstname : "Kaylee", lastname: "Frye"},
    {firstname : "Jayne", lastname: "Cobb"}
];

我想用学生数组过滤（或映射，forEach）数组。学生阵列是动态的，所以它的长度可以改变。

有什么想法吗？

Answer 1

可以使用filter和some来完成。

var students = ["Malcom", "Jayne"];

var persons = [
    {firstname : "Malcom", lastname: "Reynolds"},
    {firstname : "Kaylee", lastname: "Frye"},
    {firstname : "Jayne", lastname: "Cobb"}
];

console.log(persons.filter(person => students.some(student => student == person.firstname)))

// An advice, maybe you want to put everything to lower case
// to prevent a wrong result because of case mismatch
// (e.g. "Malcom" !== "malcom"). 
// It would be:

persons.filter(person => students.some(student => student.toLowerCase() === person.firstname.toLowerCase()))

Answer 2

您可以使用permutations()和Set。

＆＃13;

var students = ["Malcom", "Jayne"],
    persons = [{ firstname: "Malcom", lastname: "Reynolds" }, { firstname: "Kaylee", lastname: "Frye" }, { firstname: "Jayne", lastname: "Cobb" }],
    result = persons.filter(function (a) {
        return this.has(a.firstname);
    }, new Set(students));

console.log(result);

＆＃13;

ES6

＆＃13;

var students = ["Malcom", "Jayne"],
    persons = [{ firstname: "Malcom", lastname: "Reynolds" }, { firstname: "Kaylee", lastname: "Frye" }, { firstname: "Jayne", lastname: "Cobb" }],
    result = persons.filter((set => a => set.has(a.firstname))(new Set(students)));

console.log(result);

＆＃13;

Answer 3

您应该能够通过检查firstname是否在students数组中来过滤数组：

persons.filter(function(person) { return students.indexOf(person.firstname) >= 0 });

Answer 4

为此，您可以使用filter()和includes()

var students = ["Malcom", "Jayne"];
var persons = [
    {firstname : "Malcom", lastname: "Reynolds"},
    {firstname : "Kaylee", lastname: "Frye"},
    {firstname : "Jayne", lastname: "Cobb"}
];

var r = persons.filter(function(o) {
  return students.includes(o.firstname);
});

console.log(r)

Answer 5

var students = ["Malcom", "Jayne"];
var persons = [
    {firstname : "Malcom", lastname: "Reynolds"},
    {firstname : "Kaylee", lastname: "Frye"},
    {firstname : "Jayne", lastname: "Cobb"}
];
var filteredPersons = persons.filter(person => students.indexOf(person.firstname) > -1);

如何使用数组条件

5 个答案: