Kai Guo kaiguogit

tmux cheat sheet

(C-x means ctrl+x, M-x means alt+x)

Prefix key

The default prefix is C-b. If you (or your muscle memory) prefer C-a, you need to add this to ~/.tmux.conf:

remap prefix to Control + a

Each of these commands will run an ad hoc http static server in your current (or specified) directory, available at http://localhost:8000. Use this power wisely.

Discussion on reddit.

Python 2.x

$ python -m SimpleHTTPServer 8000

Q: Why don't have to write conditional statement to determine whether input is object or array? A: because Object.keys behave similarly when input is input or object, It returns an array of index when input is an array. See below example from MDN doc.

var arr = ['a', 'b', 'c']; console.log(Object.keys(arr)); // console: ['0', '1', '2']

Q: How do you think the word "cascading" in "Cascading Style Sheets" relates to specificity?

A: Cascading means while multiple rules applies to one element, the more specific rule override general rule. The latest applied rule override rules applied earlier.

Q: text in h1 is blank A:

There could be another style sheet applied later, (or closer) to the element that override the style

	const { rxObserver } = require('api/v0.3');
	const { timer, combineLatest } = require('rxjs');
	const { take, filter } = require('rxjs/operators');


	const a$ = timer(0, 10).pipe(
	take(5)
	);

	const b$ = timer(0, 4).pipe(


	var response={
	authors:[
	{
	id: 1,
	name: "Monica",
	posts: [
	{
	id: 1,
	title: "how to write fast js",

	1.
	Q: A function doesn't have to return in order to be called a closure. Simply accessing variables outside of the immediate lexical scope creates a closure.
	A: Nested functions, inner function access the outer function's variable. Then it's a closure, whether or not it return the variable to make it accessible outside.
	2.
	Q:function getMaxOfArray(numArray) {
	return Math.max.apply(null, numArray);
	}
	A: This apply method takes an array as argument instead of argument list, so that we can use an array like object as argument.
	getMaxOfArray([1,2,3]) instead of Math.max(1,2,3)
	3.

	function arrayOfLight(number){
	var a = [];
	for(i=0; i<=number; i++){
	a.push(i);
	}
	return a;
	}

	--Exercise 1
	--Fetch ISBN of all book editions published by the publisher "Random House". You should have 3 results.
	SELECT e.isbn
	FROM editions AS e
	JOIN publishers AS p ON (e.publisher_id = p.id)
	WHERE p.name = 'Random House';

	--Exercise 2
	--Instead of just their ISBN number, fetch their Book Title as well. You should still have the same 3 results but with more information. But instead of just one column, we should have 2 columns in the result set.
	SELECT e.isbn, b.title