ameenross

<?php

/**
 * @param string $regex
 * @return bool
 */
function isValidRegularExpression($regex) {
    set_error_handler(function() {}, E_WARNING);
    $valid = preg_match($regex, null) !== FALSE;
    restore_error_handler();

rauschma

Cheat sheet: JavaScript Array methods

Deriving a new Array from an existing Array:

['■','●','▲'].slice(1, 3)          ⟼ ['●','▲']
['■','●','■'].filter(x => x==='■') ⟼ ['■','■']
    ['▲','●'].map(x => x+x)        ⟼ ['▲▲','●●']
    ['▲','●'].flatMap(x => [x,x])  ⟼ ['▲','▲','●','●']

dkhorev

#!/usr/bin/env bash

sudo apt update
sudo apt -y install curl

# Set up PHP 8.0
sudo apt update
sudo apt -y install software-properties-common
sudo add-apt-repository ppa:ondrej/php
sudo apt update