directivesv3/von.html

<html>

<body>
    <script src="https://unpkg.com/vue@3"></script>

    <div id="app">
        <button @click="increase">Augmenter</button>
        <button @click.once="decrease">Diminuer</button>
        <p>{{ value }}</p>
    </div>

    <script>
        const { createApp, ref } = Vue

        createApp({
            setup() {
                const value = ref(0)

                function increase() {
                    value.value++;
                }
                function decrease() {
                    value.value--;
                }

                return { value, increase, decrease }
            }
        }).mount('#app');
    </script>
</body>

</html>