index5.html

<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8" />
        <meta http-equiv="X-UA-Compatible" content="IE=edge" />
        <meta name="viewport" content="width=device-width, initial-scale=1.0" />
        <title>Document</title>
        <script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
    </head>
    <body>
        <div id="example">
            <p>Original message: "{{ message }}"</p>
            <p>Computed reversed message: "{{ reversedMessage }}"</p>
        </div>
        <p>Reversed message: "{{ reversedMessage() }}"</p>
    </body>
    <script>
        var vm = new Vue({
            el: "#example",
            data: {
                message: "Hello",
            },
            computed: {
                // 计算属性的 getter
                reversedMessage: function () {
                    // `this` 指向 vm 实例
                    return this.message.split("").reverse().join("");
                },
            },
            methods: {
                reversedMessage: function () {
                    return this.message.split("").reverse().join("");
                },
            },
        });
        console.log(vm.reversedMessage);
        vm.message = "Goodbye";
        console.log(vm.reversedMessage);
    </script>
</html>