quiz.js

const quiz = new Vue({
    el: "#quiz",
    data() {
        return {
            product: {},
            show: {},
            choices: {
                questions: [],
                options: []
            },
            typeShow: 'questions',
            lastShow: 0,
            user: {
                name: '',
                email: '',
                city: '',
                state: 'SP',
                address: ''
            }
        }
    },

    methods : {
        /**
         * Selects the values of the options
         *
         * @returns {*}
         */
        selectValue()
        {
            var choice = {
                title: this.show.title,
                values: [],
            };
            choice.values = this.show.values.filter(function(value){
                return value.selected;
            });

            this.choices.questions.push(choice);
            return this.changeQuiz();
        },

        /**
         * Selects the answer of the questions
         *
         * @param keyAnswer
         * @returns {*}
         */
        selectAnswer(keyAnswer)
        {
            var answer = this.show.answers[keyAnswer];
            if(!answer)
                return alert("Selecione uma resposta válida");

            var choice = {
                title: this.show.title,
                answer: answer.title,
                price: answer.price
            };

            this.choices.options.push(choice);
            return this.changeQuiz();
        },

        /**
         * Change the quiz being shown
         *
         * @returns {*}
         */
        changeQuiz()
        {
            this.lastShow++;
            var nextInfo = this.product[this.typeShow][this.lastShow];

            if(!nextInfo && this.typeShow == 'options'){
                return this.finishQuiz();
            }

            if(!nextInfo){
                this.lastShow = 0;
                this.show = this.product.options[this.lastShow];

                return this.typeShow = 'options';
            }

            return this.show = nextInfo;
        },

        finishQuiz()
        {
            this.typeShow = 'contact';
        }
    },

    /**
     * This hook is not called during server-side rendering.
     */
    mounted() {
        this.product = window.product;

        this.show = this.product.questions[0];
        this.typeShow = 'questions';
    }
});