underscore-chain.js

//Example of underscore chaining
var users = [
  {name: 'John', surname: 'Doe', age: 35},
  {name: 'John 2', surname: 'Doe 2', age: 19},
  {name: 'John 3', surname: 'Doe 3', age: 28},
  {name: 'John 4', surname: 'Doe 4', age: 16},
  {name: 'John 5', surname: 'Doe 5', age: 39}
];

//Iterate over users and sort them by age, pick first and transform to a sentence
var res = _.chain(users)
  .filter(function (user) {
    return user.age > 20;
  })
  .sortBy(function (user) {
    return -user.age;
  })
  .map(function (user) {
    return 'My name is ' + user.name + ' ' + user.surname + ', and I\'m ' + user.age + ' old';
  })
  .first()
  .value();
  
console.log(res); //My name is John 5 Doe 5, and I'm 39 old

//We could also reuse the functions and get something as:
// var res = _.chain(users)
//   .filter(ageOver.bind(null, 20))
//   .sortBy(sortByAge) //or use also _.negate(sortByAge) to get different effect
//   .map(formatUserTitle)
//   .first()
//   .value();

//Same thing with ES6
// var res = _.chain(users)
//   .filter(user => user.age > 20)
//   .sortBy(user => -user.age)
//   .map(user => `My name is ${user.name} ${user.surname} and I'm ${user.age} old`)
//   .first()
//   .value();