How to do equivalent of LINQ SelectMany() just in javascript

Question

Unfortunately, I don't have JQuery or Underscore, just pure javascript (IE9 compatible).

I'm wanting the equivalent of SelectMany() from LINQ functionality.

// SelectMany flattens it to just a list of phone numbers. IEnumerable<PhoneNumber> phoneNumbers = people.SelectMany(p => p.PhoneNumbers); 

Can I do it?

EDIT:

Thanks to answers, I got this working:

var petOwners =  [     {         Name: "Higa, Sidney", Pets: ["Scruffy", "Sam"]     },     {         Name: "Ashkenazi, Ronen", Pets: ["Walker", "Sugar"]     },     {         Name: "Price, Vernette", Pets: ["Scratches", "Diesel"]     }, ];  function property(key){return function(x){return x[key];}} function flatten(a,b){return a.concat(b);}  var allPets = petOwners.map(property("Pets")).reduce(flatten,[]);  console.log(petOwners[0].Pets[0]); console.log(allPets.length); // 6  var allPets2 = petOwners.map(function(p){ return p.Pets; }).reduce(function(a, b){ return a.concat(b); },[]); // all in one line  console.log(allPets2.length); // 6 

Answer 1

for a simple select you can use the reduce function of Array.
Lets say you have an array of arrays of numbers:

var arr = [[1,2],[3, 4]]; arr.reduce(function(a, b){ return a.concat(b); }, []); =>  [1,2,3,4]  var arr = [{ name: "name1", phoneNumbers : [5551111, 5552222]},{ name: "name2",phoneNumbers : [5553333] }]; arr.map(function(p){ return p.phoneNumbers; })    .reduce(function(a, b){ return a.concat(b); }, []) =>  [5551111, 5552222, 5553333] 

Edit:
since es6 flatMap has been added to the Array prototype. SelectMany is synonym to flatMap.
The method first maps each element using a mapping function, then flattens the result into a new array. Its simplified signature in TypeScript is:

function flatMap<A, B>(f: (value: A) => B[]): B[] 

In order to achieve the task we just need to flatMap each element to phoneNumbers

arr.flatMap(a => a.phoneNumbers);