Anand Gupta anandgupta193

Eric Elliott's "Master the JavaScript Interview" Series

A collection of links to the "Master the JavaScript Interview" series of medium stories by Eric Elliott.

Not part of the series but a good grounding.

Master the JavaScript Interview

@kangax's ES6 quiz, explained

@kangax created a new interesting quiz, this time devoted to ES6 (aka ES2015). I found this quiz very interesting and quite hard (made myself 3 mistakes on first pass).

Here we go with the explanations:

Question 1:

(function(x, f = () =&gt; x) {

	const combineReducers = (reducers) => (state = {}, action) => Object.keys(reducers).reduce((nextState, key) => {
	nextState[key] = reducers[key](state[key], action);
	return nextState;
	}, {});

	1-In the github repo on Settings > Integration & Services, enable
	2-Go to travisCI page and enable the repo
	3-Configure the env variables on TravisCI so that it is not necessary to save credentials on github
	-in the project Settings on TravisCI, add the entry for netlify site id: NETLIFY_SITE_ID - <site_id from .netlify file generated on netlify create>
	-create a netlify access token for TravisCI
	-On Netlify Dashboard, Go to Account Settings > OAuth Applications (https://app.netlify.com/account/applications) > Personal access tokens and press New Access Token
	-Name it anything, but to make it easier the suggestion is name TravisCI.
	-Generate it and COPY it - you won’t see it again!
	-in the project Settings on TravisCI, add the entry for netlify personal access token generated for TravisCI: NETLIFY_ACCESS_TOKEN
	4-Generate a .travis.yml file in the local repo

	// https://jsfiddle.net/vk35ok2o/50/
	console.log('typeof 1/0 => ', typeof 1/0);
	console.log('typeof (1/0) => ', typeof (1/0));
	console.log('1/0 => ', 1/0);
	console.log('"Hello" * 2 => ', "Hello" * 2);
	console.log('typeof ("Hello" * 2) => ', typeof ("Hello" * 2));
	console.log('typeof "Hello" * 2 => ', typeof "Hello" * 2);
	console.log('typeof undefined => ', typeof undefined);
	console.log('typeof null => ', typeof null);
	console.log('typeof function(){} => ', typeof function(){});

	if (!Array.isArray) {
	Array.isArray = function(arg) {
	return Object.prototype.toString.call(arg) === '[object Array]';
	};
	}