JavaScript in 100 Seconds

javascript a high level single threaded garbage collected interpreted or just in time compiled prototype-based multi-paradigm dynamic language with a non-blocking event loop made famous for

building websites it was created in 1995 in just one week by brendan ike with the goal of adding an easy to learn scripting language to the netscape browser it was originally named mocha but the genius marketing people of the

time wanted it to sound like that sexy new java language today it's a fully featured language that continues to evolve through the ecmascript standard it's most well known for building front-end web applications because it's the only language other than web

assembly that is natively supported in browsers however anything that can be built with javascript will be built with javascript like server-side applications with node.js mobile applications with

react native or ionic and desktop apps with electron it's an interpreted scripting language but tools like the v8 engine and chromium use a just-in-time compiler to convert it to machine code

at runtime it's also excellent at handling i o intensive jobs despite the fact that it's a single threaded language made possible by a non-blocking event loop that can queue up work in the background without blocking the main

thread to get started create a file ending in.js your code will start executing from the global context use the console to log a value with the built-in debugger now think about where you want to run this file is it a

front-end browser or a back-end node.js server in the browser you can reference it with a script tag then the browser will execute it when you open that html file on a website javascript is often used to grab an element from the dom

document query selector will grab the first button then we can assign it to a variable with either var let or const var is the og way to do it but is typically avoided let is for variables that can be reassigned while const is

for variables that cannot be reassigned now to make the button interactive we can add an event listener to it by defining a function for the on click event we can use the function keyword here or the more concise arrow syntax

now the event loop will execute this function whenever a new click occurs functions are first class objects to support functional programming patterns but javascript also supports classes and inheritance for object oriented patterns

even though it's single threaded it can do work asynchronously with the promise api which also supports the async await syntax js code can also run on the server thanks to the nodejs runtime

instead of buttons on a web page it interacts with things like the file system api execute your code on the server by pulling up the terminal and entering the node command this has been javascript in 100 seconds hit the like

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