1. Understand the Basics

Before diving into advanced tips and tricks, ensure you have a strong grasp of JavaScript’s fundamentals. This includes variables, data types, functions, and control structures. A solid foundation is key to mastering the language.

2. Use Modern Syntax

JavaScript continually evolves, introducing new features and syntax improvements. Stay up-to-date with the latest ECMAScript standards (ES6 and beyond) to write cleaner and more efficient code. Features like arrow functions, destructuring, and the let and const variable declarations can make your code more readable.

3. Embrace Functional Programming

Functional programming principles can simplify your code and make it more maintainable. Learn about higher-order functions like map, filter, and reduce to work with arrays in a more elegant way. Utilize closures, pure functions, and immutability to reduce bugs and enhance your code’s reliability.

4. Master the DOM

Manipulating the Document Object Model (DOM) is a fundamental skill in web development. Use querySelector and querySelectorAll for efficient DOM traversal. Learn how to create, append, and remove elements to create dynamic web applications.

5. Error Handling

Always handle errors gracefully. Use try…catch blocks to catch and handle exceptions, ensuring that your code doesn’t break unexpectedly. Proper error handling improves the user experience and makes debugging more straightforward.

6. Async/Await

Working with asynchronous code is a common challenge in JavaScript. Utilize async/await to simplify asynchronous operations and make your code more readable. Avoid callback hell by using Promises and async functions.

7. Object-Oriented JavaScript

Understand object-oriented programming (OOP) principles in JavaScript. Learn how to create and work with classes, constructors, and prototypes to structure your code effectively. This will lead to more organized and maintainable applications.

8. Leverage Libraries and Frameworks

JavaScript has a vast ecosystem of libraries and frameworks like React, Angular, and Vue.js for building web applications. Familiarize yourself with one or more of these to speed up development and create powerful, interactive interfaces.

9. Code Splitting

For improved performance and user experience, use code splitting techniques. Divide your JavaScript code into smaller, manageable parts and load them on-demand to reduce initial page load times.

10. Testing and Debugging

Writing automated tests and using debugging tools like the browser’s DevTools can save you countless hours of debugging. Master these skills to find and fix issues quickly.

Cheat Codes:

Now, let’s explore some “cheat codes” – quick solutions to common JavaScript challenges:

1. Short-Circuit Evaluation

Use the && and || operators for concise conditionals. For example, variable && functionToExecute() will only execute functionToExecute() if variable is truthy.

2. Object Destructuring

Object destructuring allows you to extract specific properties from an object easily. For instance, { name, age } = person assigns the name and age properties from the person object to variables of the same name.

3. Ternary Operator

The ternary operator (condition ? trueCase : falseCase) simplifies if-else statements, making your code more concise.

4. Template Literals

Template literals (${variable}) enable string interpolation, making it easy to create dynamic strings without complex concatenation.

5. Array Spread and Rest

Use the spread operator (...) to copy arrays, combine arrays, or pass multiple arguments to a function. The rest parameter (...args) collects multiple arguments into an array.

JavaScript Strings
As mentioned earlier, Strings are nothing but a combination of characters that can be used to perform a variety of tasks. JavaScript provides so many methods for Strings alone that it makes sense to cover Strings as a standalone topic in this cheat sheet. Let us now look at the various escape sequences in JavaScript and the methods which JavaScript provides for strings:

Escape Sequences or Escape Characters: An escape character is a character in computers and telecommunications that causes the following characters in a character sequence to take on a different meaning. Metacharacters include escape characters, which are a subset of metacharacters. In general, whether something is an escape character or not is determined by the context. For instance, Strings in JavaScript are delimited by single or double-quotes. You must use special characters in a string if you want to utilise quote marks. A few of the escape characters allowed by JavaScript are as follows:
\’ — Single quotes
\” — Double quotes
\t — Horizontal tab
\v — Vertical tab
\ — Backslash
\b — Backspace
\f — Form feed
\n — Newline
\r — Carriage return

Document Object Model (DOM) in JavaScript
The Document Object Model (DOM) is the structure of a webpage’s code. There are many different ways to build and alter HTML elements with JavaScript (called nodes).

Node Properties: Let us first take a look at some of the properties of a JavaScript DOM node:
attributes — Gets a live list of all the characteristics associated with an element.
baseURI — Returns an HTML element’s absolute base URL.
childNodes — Returns a list of the child nodes of an element.
firstChild — Returns the element’s first child node.
lastChild — An element’s final child node
nextSibling — Returns the next node in the same node tree level as the current node.
nodeName —Returns a node’s name.
nodeType — Returns the node’s type.
nodeValue — Sets or returns a node’s value.
ownerDocument — This node’s top-level document object.
parentNode — Returns the element’s parent node.
previousSibling — Gets the node that comes before the current one.
textContent — Sets or returns a node’s and its descendants’ textual content.

JavaScript Date Objects
Dates are extremely important to deal with while creating most types of applications. JavaScript also allows you to deal with and change dates and times. The next section of the JavaScript cheat sheet is how to work on dates:

Setting Dates: Dates can be set using the following three ways:
Date() — Returns a new date object that contains the current date and time.
Date(1993, 6, 19, 5, 12, 50, 32) — We can create a custom date object with the pattern as Year, month, day, hour, minutes, seconds, and milliseconds are represented by the numbers. Except for the year and month, we can omit anything we like.
Date(“1999-12-22”) — Date as a string declaration
Getting the values of Time and Date: The following methods can be used for getting the date and time values in JavaScript:
getDate() returns the month’s day as a number (1-31)
getTime() — Get the milliseconds since January 1, 1970
getUTCDate() returns the month’s day (day) in the supplied date in universal time (also available for day, month, full year, hours, minutes etc.)
getMilliseconds() — This function returns the milliseconds (0-999)
getMinutes() — Returns the current minute (0-59)
getMonth() returns the current month as a number (0-11)
parse — It returns the number of milliseconds since January 1, 1970 from a string representation of a date.
getDay() returns a number representing the weekday (0-6)
getFullYear() returns the current year as a four-digit value (yyyy)
getHours() — Returns the current hour (0-23)
getSeconds() — Returns the second number (0-59)
Setting a Part of the Dates: We can set a part of the dates in JavaScript using the following methods:
setDate() — Returns the current date as a number (1-31)
setFullYear() — This function sets the year (optionally month and day)
setMonth() — This function sets the month (0-11)
setSeconds() — This function sets the seconds (0-59)
setTime() — This function is used to set the time (milliseconds since January 1, 1970)
setMinutes() — This function sets the minutes (0-59)
setUTCDate() — According to universal time, sets the day of the month for a given date (also available for day, month, full-year, hours, minutes etc.)
setHours() — Changes the time (0-23)
setMilliseconds() — This function sets the milliseconds (0-999)

JavaScript Events
Things that can happen to HTML components and are executed by the user in JavaScript are called events. These events can be detected by the programming language, which can then be used to activate code actions. Without them, no JavaScript cheat sheet would be complete. Let us take a look at some of the events supported by JavaScript:

Mouse Events:
onclick – When a user clicks on an element, an event is triggered.
oncontextmenu — When a user right-clicks on an element, a context menu appears.
ondblclick — When a user double-clicks on an element, it is called ondblclick.
onmousedown — When a user moves their mouse over an element, it is called onmousedown.
onmouseenter — The mouse pointer is moved to a certain element.
onmouseleave — The pointer leaves an element.
onmousemove — When the pointer is over an element, it moves.
onmouseover — When the cursor is moved onto an element or one of its descendants, the term onmouseover is used.
onmouseout — When the user moves the mouse cursor away from an element or one of its descendants, it is called onmouseout.
onmouseup — When a user releases a mouse button while hovering over an element, it is known as onmouseup.
Form Events:
onblur — When an element loses focus, it is called onblur.
onchange — A form element’s content changes. (for the input>, select>, and textarea> elements)
onfocus – An aspect is brought into focus.
onfocusin — When an element is ready to become the centre of attention.
onfocusout —The element is about to lose focus.
oninput — When a user inputs something into an element, it’s called oninput.
oninvalid — If an element isn’t valid, it’s called oninvalid.
onreset — The state of a form is reset.
onsearch — A user enters text into a search field (for input=”search”>).
onselect — The user chooses some text (input> and textarea>).
onsubmit — A form is filled out and submitted.
Drag Events:
ondrag — When an element is dragged, it is called ondrag.
ondragend — The element has been dragged to its final position.
ondragenter — When a dragged element enters a drop target, it is called ondragenter.
ondragleave — When a dragged element departs the drop target, it is called ondragleave.
ondragover — The dropped element is on top of the dragged element.
ondragstart — The user begins dragging an element.
ondrop — When a dragged element is dropped on a drop target, it is called ondrop.
Keyboard Events:
onkeydown — When the user presses a key down
onkeypress — When the user begins to press a key.
onkeyup — A key is released by the user.
Frame Events:
onabort — The loading of a media is aborted with onabort.
onerror — When loading an external file, an error occurs.
onpagehide – When a user leaves a webpage, it is called onpagehide.
onpageshow — When the user navigates to a webpage
onhashchange — The anchor component of a URL has been changed.
onload — When an object has loaded
onresize — The document view gets resized when onresize is called.
onscroll — The scrollbar of an element is being scrolled.onbeforeunload — Before the document is due to be emptied, an event occurs.
onunload — When a page is emptied, this event occurs.
Animation Events:
animationstart — The animation in CSS has begun.
animationend — When a CSS animation is finished, it is called animationend.
animationiteration — CSS animation is repeated using animationiteration.
Clipboard Events:
oncut — The content of an element is cut by the user.
onpaste — When a user pastes material into an element, it is called onpaste.
oncopy — The content of an element is copied by the user.
Media Events:
onloadeddata — Media data has been loaded
onloadedmetadata — Metadata is loaded (such as size and duration).
onloadstart — The browser begins looking for the media that has been specified.
onabort — The loading of media has been halted.
onerror — When an error occurs while loading an external file, the event onerror is triggered.
onpause — Media is paused, either manually or automatically, by the user.
onplay — The video or audio has begun or is no longer paused.
onstalled — The browser is attempting to load the media, but it is not currently accessible.
oncanplay — The browser has the ability to begin playing media (e.g. a file has buffered enough)
oncanplaythrough — The browser is capable of playing media without pausing.
ondurationchange — The media’s duration changes.
onended — The media’s time has come to an end.
onsuspend — The browser is not loading media on purpose.
ontimeupdate — The situation has shifted (e.g. because of fast forward)
onvolumechange — The volume of the media has changed (including mute)
onwaiting — The media has taken a break, but it is anticipated to resume soon (for example, buffering)
onplaying — Media that has been paused or halted for buffering is now playing.
onprogress — The media is being downloaded by the browser.
onratechange — The media’s playback speed changes.
onseeking — The user begins to move/skip.
Miscellaneous Events:
transitionend — When a CSS transition is complete, this event is triggered.
onmessage — The event source has received a message.
onpopstate — When the history of the window changes
onshow — A element is shown as a context menu when it is onshow.
onoffline — The browser switches to offline mode.
ononline — The browser enters the online mode.
ontouchcancel — The user’s ability to touch the screen has been halted.
ontouchstart — The touch-screen is activated by placing a finger on it.
onstorage — An part of Web Storage has been upgraded.
ontoggle — The user toggles the details> element open or closed.
onwheel — The mouse wheel moves up and down when it passes over an element.
ontouchend — A touch-screen user’s finger is withdrawn.
ontouchmove — When a finger is dragged over the screen, it is called ontouchmove.