BirthME, Doulas

It's so popular that everything new that shows up is going to have some kind of JavaScript integration at some point.Created in 1995, JavaScript has gone a very long way since its humble beginnings.It was the first scripting language that was supported natively by web browsers, and thanks to this it gained a competitive advantage over any other language and today it's still the only scripting language that we can use to build Web Applications.Other languages exist, but all must compile to JavaScript - or more recently to WebAssembly, but this is another story.In the begining, JavaScript was not nearly powerful as it is today, and it was mainly used for fancy animations and the marvel known at the time as With the growing needs that the web platform demanded (and continues to demand), JavaScript JavaScript is also now widely used outside of the browser. JavaScript is one of the most popular programming languages in the world.I believe it's a great choice for your first programming language ever.but JavaScript is not limited to these things, and it can also be used toIt can basically do anything. If you assign a bigger number than the arrays current capacity, nothing happens. �X���H��@�����5��d"o��X�*}C�O��Γ�bhF�4�(ӆ��C��>6��j�=�ax���rwj�����|�J���D�%e�=g�*F Or is it "plain JavaScript", or "vanilla JavaScript" as it's often called?In this book I talk about JavaScript, the language.Without complicating your learning process with things that are outside of it, and provided by external ecosystems.In this little introduction I want to tell you about 5 concepts:JavaScript does not consider white space meaningful. Traitement des variables déclarées avec var, qui sont Lorsque l'on veut créer une fonction, cela veut dire que nous avons du code et ce code nous souhaitons le réutiliser. Spaces and line breaks can be added in any fashion you might like, at least In practice, you will most likely keep a well defined style and adhere to what people commonly use, and enforce this using a linter or a style tool such as For example, I always use 2 space characters for each indentation.The dollar sign is commonly used to reference DOM elements.Some names are reserved for JavaScript internal use, and we can't use them as identifiers.Comments are one of the most important parts of any program, in any programming language. %PDF-1.4 Our mission: to help people learn to code for free. They are especially useful to make multiline strings much simpler. The first is to use You can declare multiple variables at once in the same statement:But you cannot redeclare the same variable more than one time:Variables in JavaScript do not have any type attached.Once you assign a value with some type to a variable, you can later reassign the variable to host a value of any other type without any issues.Any value that's not of a primitive type (a string, a number, a boolean, null or undefined) is an An expression is a single unit of JavaScript code that the JavaScript engine can evaluate, and return a value.We start from the very simple ones, called primary expressions:Arithmetic expressions are expressions that take a variable and an operator (more on operators soon), and result in a number:String expressions are expressions that result in a string:Logical expressions make use of logical operators and resolve to a boolean value:More advanced expressions involve objects, functions, and arrays, and I'll introduce them later.Operators allow you to get two simple expressions and combine them to form a more complex expression.We can classify operators based on the operands they work with. The first is a function we call to resolve the promise, the second a function we call to reject the promise.Resolving a promise means to complete it successfully (which results in calling the Rejecting a promise means ending it with an error (which results in calling the We can pass a parameter to the resolve and reject functions, of any type we want.Async functions are a higher level abstraction of promises.An async function returns a promise, like in this example:Any code that wants to use this function will use the and doing so, any data returned by the promise is going to be assigned to the The async/await duo allows us to have a cleaner code and a simple mental model to work with asynchronous code.As you can see in the example above, our code looks very simple.