javascript: closures

closures.js

// 1-basic
console.log('++++++++++++++++++++++++++++++++++++++++++++++++++');
const count = (() => {
  let currentValue = 0;
  return () => currentValue += 1;
})();

console.log('count:', count()); //1
console.log('count:', count()); //2
console.log('count:', count()); //3
console.log('count:', count()); //4

// 2-basic
console.log('++++++++++++++++++++++++++++++++++++++++++++++++++');
const outsite = () => {
  let num = 0;
  //return () => ++num;
  return () => num++;
}

const increase = outsite();

console.log('outsite', outsite()());  //0
console.log('increase:', increase()); //0
console.log('increase:', increase()); //1
console.log('increase:', increase()); //2
console.log('increase:', increase()); //3
console.log('outsite', outsite()());  //0

// 3-basic
console.log('++++++++++++++++++++++++++++++++++++++++++++++++++');
const outsite_2 = a => b => a += b;

console.log('outsite_2:', outsite_2(1)(3)); //4
console.log('outsite_2:', outsite_2(10)(5));//15

const base = outsite_2(5);

console.log('base:', base(1));  //6
console.log('base:', base(4));  //10
console.log('base:', base(10)); //20
console.log('base:', base(100));//120

// 2-fetch
console.log('++++++++++++++++++++++++++++++++++++++++++++++++++');
require('isomorphic-fetch');
// npm i -S isomorphic-fetch
// npm closures.js
// rm -rf node_modules package-lock.json

const crudder = domain => resource => {
  const url = `${domain}/${resource}`;
  return ({
    create: (x) => fetch(url, {
      method: 'POST',
      body: JSON.stringify(x)
    }).then(resp => resp.json()),
    get: () => fetch(url).then(resp => resp.json())
  });
}

const baseUrl = crudder('https://jsonplaceholder.typicode.com');
const all = baseUrl('todos');
const users = baseUrl('users');
const post = baseUrl('posts');

all.get().then(resp => console.log('all:', resp[0]));
users.get().then(resp => console.log('users:', resp[0]));

post.create({
  userId: 1,
  title: 'My Love',
  body: 'Dolor quidem ut rerum dolor?'
}).then(console.log);

//output
//++++++++++++++++++++++++++++++++++++++++++++++++++
//count: 1
//count: 2
//count: 3
//count: 4
//++++++++++++++++++++++++++++++++++++++++++++++++++
//outsite 0
//increase: 0
//increase: 1
//increase: 2
//increase: 3
//outsite 0
//++++++++++++++++++++++++++++++++++++++++++++++++++
//outsite_2: 4
//outsite_2: 15
//base: 6
//base: 10
//base: 20
//base: 120
//++++++++++++++++++++++++++++++++++++++++++++++++++
//users: {
//  id: 1,
//  name: 'Leanne Graham',
//  username: 'Bret',
//  email: '[email protected]',
//  address: {
//    street: 'Kulas Light',
//    suite: 'Apt. 556',
//    city: 'Gwenborough',
//    zipcode: '92998-3874',
//    geo: { lat: '-37.3159', lng: '81.1496' }
//  },
//  phone: '1-770-736-8031 x56442',
//  website: 'hildegard.org',
//  company: {
//    name: 'Romaguera-Crona',
//    catchPhrase: 'Multi-layered client-server neural-net',
//    bs: 'harness real-time e-markets'
//  }
//}
//all: { userId: 1, id: 1, title: 'delectus aut autem', completed: false }
//{ id: 101 }