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                <!DOCTYPE html>
        <title>Cours JavaScript</title>
        <meta charset="utf-8">
        <link rel="stylesheet" href="cours.css">
        <script src='cours.js' async></script>
        <h1>Titre principal</h1>
        <p>Un premier paragraphe</p>
        <button>Cliquez moi !</button>
            <p>Un paragraphe dans un div</p>
            <p>Un autre paragraphe dans le div</p>




                //On sélectionne le premier button et le premier div du document
let b1 = document.querySelector('button');
let d1 = document.querySelector('div');

function changeCouleur(){ ='orange';

//On utilise la méthode addEventListener pour gérer des évènements
b1.addEventListener('click', function(){alert('Bouton cliqué')});
d1.addEventListener('mouseover', changeCouleur);
d1.addEventListener('mouseover', function(){ ='bold'});

//On supprime un évènement
d1.removeEventListener('mouseover', changeCouleur);