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HTML

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CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

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JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient.

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Babel includes JSX processing.

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You can apply a script from anywhere on the web to your Pen. Just put a URL to it here and we'll add it, in the order you have them, before the JavaScript in the Pen itself.

If the script you link to has the file extension of a preprocessor, we'll attempt to process it before applying.

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Packages

Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.

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Using packages here is powered by esm.sh, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ESM usage.

All packages are different, so refer to their docs for how they work.

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HTML 

              
                <!DOCTYPE html>
<html>
    <head>
        <title>Cours JavaScript</title>
        <meta charset="utf-8">
        <meta name="viewport"
          content="width=device-width, initial-scale=1, user-scalable=no">
        <link rel="stylesheet" href="cours.css">
        <script src='cours.js' async></script>
    </head>
    
    <body>
        <h1>Titre principal</h1>
        <p>Un paragraphe</p>
        <p id='p1'></p>
        <p id='p2'></p>
        <p id='p3'></p>
        <p id='p4'></p>
        <p id='p5'></p>
    </body>
</html>
!

CSS
!

JS 

              
                //On déclare deux variables globales
let x = 5;
var y = 10;

//On définit une première fonction qui utilise les variables globales
function portee1(){
    document.getElementById('p1').innerHTML =
    'Depuis portee1() : <br>x = ' + x + '<br>y = ' + y;
}
//On définit une deuxième fonction qui définit des variables locales
function portee2(){
    let a = 1;
    var b = 2;
    document.getElementById('p2').innerHTML =
    'Depuis portee2() : <br> a = ' + a + '<br>b = ' + b;
}
//On définit une troisième fonction qui défnit également des variables locales
function portee3(){
    let x = 20;
    var y = 40;
    document.getElementById('p3').innerHTML =
    'Depuis portee3() : <br>x = ' + x + '<br>y = ' + y;
}

//On pense bien à exécuter nos fonctions !
portee1();
portee2();
portee3();

//On tente d'afficher des variables globales puis locales depuis l'espace global
document.getElementById('p4').innerHTML =
'Depuis l\'espace global : <br>x = ' + x + '<br>y = ' + y;

document.getElementById('p5').innerHTML =
'Depuis l\'espace global : <br>a = ' + a + '<br>b = ' + b;
!
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