Example list of objects

ExampleUserList.js

const getValue = property => obj => obj && obj[property];

// Example List of users
const users = [{
    name: 'sarah',
    id: '12345',
    country: 'Australia',
},
{
  name: 'bob',
  id: '34325',
  country: 'New Zealand',
},
{
  name: 'Sam',
  id: '42524',
  country: 'Australia',
},
{
  name: 'Roger',
  country: 'USA',
  id: '314135'
}];

users.map(getValue('id')); 
// result: ['12345', '34325', '42524', '314135']

/**
    Every array value is being passed a function - the result of getValue('id')
    which looks like this (obj) => obj && obj[property]; 
    it has retained value ('id') from the outter call
    which then returns '12345', '34325', '42524', '314135'
**/