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#!/usr/bin/env bash

for f in *
  do qpdf --password=THE_PASSWORD --decrypt --replace-input $f;
done


# brew install qpdf
# for executable file run: chmod u+x decrypt-pdf.sh
# merge files into one PDF: `qpdf --empty --pages *.pdf -- out.pdf`

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Table of Contents generated with DocToc

• FrontEnd Masters - ES6 notes
  • Proper Tail Call (PTC)
  • Function Hoisting
  • Variables
    • Temporal Dead Zone
• Rest Parameters

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What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

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Timer App

Please create an app for managing timed tasks.

1. The user can input a text and click Add
2. A new task is added with the title, and 00:00 time, and a play button.
3. Clicking Play will play this task: the timer will start running, and the icon will change to a pause icon. Also - any other running task will be paused.
4. Clicking Pause will pause the task.
5. The total time is always updated.

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import React, {
  memo,
  useMemo,
  useRef,
  useState,
  useEffect,
  useCallback
} from "react";
import { Link } from "react-router-dom";