| //require modules | |
| var request = require('request'); | |
| var cheerio = require('cheerio'); | |
| var fs = require('fs'); | |
| //prepare to reverse those strings | |
| function reverseString(str) { | |
| return str | |
| .split('') //split string into an array | |
| .reverse() // reverse the array values |
Task: Reverse the provided string in as many different ways as possible.
Tests: All the solutions should pass the following tests:
"hello" should return a string."hello" should become "olleh"."Howdy" should become "ydwoH"."Greetings from Earth" should return "htraE morf sgniteerG"Code:
Task: Write a function which returns true if the given string is a palindrome. Otherwise, return false.
Pseudocode:
Task: Return the factorial of the provided integer.
Pseudocode:
Actual Code:
Learning how to read source code has become a hobby of mine lately (and a painful one at that). In the course of my reading I have come across a number of blogs and articles on the subject which have been helpful, so I thought I'd create a gist to keep track of them and also share them easily.
How to read source code
Earlier this year at work we re-wrote an internal framework we used to create SPA e-learning courses. After briefly trying out React, Angular 2, Ember and Vue, we settled on mithril (https://mithril.js.org). If I were to compare it to the frameworks we tried out, I would say it's more like React but with a simpler, smaller codebase. By the way, if you like geeking out on code articles, the articles from mithril's old site have some real nuggets of gold (http://lhorie.github.io/mithril-blog/).
A few months after the re-write was done, I dug into mithril's codebase to gain a deeper understanding and this is what I found...
The main entry point into mithril's source code is the m() function, which is a hyperscript function that, according to the docs (https://mithril.js.org/hyperscript.html), represents an element in a mithril view. It's demonstrated below as:
m("div", {id: "box"}, "hello")
// equivalent HTML:
// <div id="box">hello</div>
Before reading a library or framework's source code, it's advisable to go through the documentation. Thankfully, mithril's size means reading through the main APIs is not that arduous a task. When reading the docs, you will often find notes from the authors detailing recommended ways of using the available features. This is useful when you read the source because you can more easily understand why certain bits of code exist. I've noted below five recommendations I came across during my latest round of reading the mithril docs. I found more than five but I'll go through the rest at a later time. The example code below each recommendation has been taken from the docs.
m("div#hello") // static
m("a.link[href=/]", {
class: currentURL === "/" ? "selected" : ""
}, "Home") // dynamic
In my first explainer of Mithril's source code, I broke down how the hyperscript function worked. It's main task is the creation of virtual DOM nodes (vnodes), the objects which represent DOM elements or parts of the DOM. So how are these objects created?
This is the function which creates a vnode:
function Vnode(tag, key, attrs, children, text, dom) {
return {tag: tag, key: key, attrs: attrs, children: children, text: text, dom: dom, domSize: undefined, state: undefined, _state: undefined, events: undefined, instance: undefined, skip: false}
}This function is assisted in its work by these two helper functions:
| ReactDOM.render( | |
| <h1>Hello, world!</h1>, | |
| document.getElementById('root'), | |
| () => {} | |
| ); |