How To Filter Array With Array Condition

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

Solution 1:

It can be done with filter along with some.

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()))

Solution 2:

You could use Set and Array#filter.

var students = ["Malcom", "Jayne"],
    persons = [{ firstname: "Malcom", lastname: "Reynolds" }, { firstname: "Kaylee", lastname: "Frye" }, { firstname: "Jayne", lastname: "Cobb" }],
    result = persons.filter(function (a) {
        returnthis.has(a.firstname);
    }, newSet(students));

console.log(result);

ES6

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))(newSet(students)));

console.log(result);

Solution 3:

You should be able to filter the array by checking if their firstname is in the students array:

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

Solution 4:

For this you can use filter() and 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)

Solution 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);