每个按钮单击JS和Symfony2后的变量重置

Question

我有单选按钮，我想在每个正确答案的最后计算显示分数。在下面的代码表中是数据库表，choice1，choice2，choice3，answer都是选项。我想最后显示总问题的总分。下面是我的javascript，每次点击下一个按钮时，js中的总和值都会重置。单击每个按钮后如何保存sum变量。 谢谢

Twig文件

{% set counter = 0 %}
    {% for table in entities %} 
        <form role="form">
            <div class="checkbox">
                <label><input type="radio"name="choices" >{{ table.choice1 }}</label>
            </div>
            <div class="checkbox">
                <label><input type="radio" name="choices">{{ table.choice2 }}</label>
            </div>
            <div class="checkbox">
                <label><input type="radio" name="choices">{{ table.choice3 }}</label>
            </div>
            <div class="checkbox">
                <label><input type="radio"name="choices" >{{ table.answer }}</label>
            </div>
        {%  if counter==entitites|length %}
                <button onclick="submitanswer()" >Submit</button>
        {% else %}
           <li> <a onclick="myFunction()" href="{{ path('view', route_params | merge({ 'id': table.Id+1 })) }}">Next</a></li>
        {% endif %}
       </form>
            {% endif %}
            {% set counter = counter+1 %}
      {% endfor %}

的Javascript

    {% block javascript %}
        <script>
            var choice, choices;
            var sum = 0;

            function myFunction() {
                choices=document.getElementsByName("choices");
                for(var i = 0; i < choices.length; i++){
                    if(choices[i].checked){
                        choice = choices[i].value;
                    }
                 }
                alert(choice);
                alert(choices[3].value);
                if(choice==choices[3].value){
                    sum += 1;
                alert(sum);
                }
                else{
                    alert(sum);
                }
                {#if(choice=={{ answer }}){#}
                  {##}
                {#}#}
                {#alert({{ entities[0].answer }});#}
                {#return sum;#}
              }   

            function submitanswer(){
                choices=document.getElementsByName("choices");
                for(var i = 0; i < choices.length; i++){
                    if(choices[i].checked){
                        choice = choices[i].value;
                    }
                }
                    if(choice==choices[3].value){
                    sum += 1;
                }
                alert(sum);
            }
            </script>
    {% endblock %}