hellerbarde

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

cecilemuller

<?php

function get_combinations($arrays) {
	$result = array(array());
	foreach ($arrays as $property => $property_values) {
		$tmp = array();
		foreach ($result as $result_item) {
			foreach ($property_values as $property_value) {
				$tmp[] = array_merge($result_item, array($property => $property_value));
			}

Kartones

PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

adamwathan

Handy helpers for controlling visibility of elements until Vue has compiled.

Use like:

<div v-cloak>
  <h1>
    <span class="v-cloak--inline">Loading...</span> <!-- Only displayed before compiling -->
    <span class="v-cloak--hidden">{{ post.title }}</span> <!-- Hidden until compiling is finished -->
 

anschaef

/* -------------------------------------------------------------------------- */
// All Bootstrap 4 Sass Mixins [Cheat sheet]
// Updated to Bootstrap v4.5.x
// @author https://anschaef.de
// @see https://github.com/twbs/bootstrap/tree/master/scss/mixins
/* -------------------------------------------------------------------------- */

/*
// ########################################################################## */
// New cheat sheet for Bootstrap 5: