Question

我正在从数据库中生成问题，用户将在下拉菜单中选择答案。当用户选择某个选项时，建议将被推送到触发JavaScript的on-change事件的数组。当用户完成所有问题后，我将把数组作为行从存储所有建议的表单发送到数据库。

当我尝试发送建议时，建议第一次被推送，但是当用户更改答案时，阵列会再次发送重复消息

<form action="">
@foreach ($questions as $question)


        {{-- <p>{{$question->id}}){{$question->english}}</p> <br> --}}


            <div class="form-group">
                <label>{{$question->id}}) {{$question->english}}</label>
                <select id="{{$question->id}}" onchange="sendSuggestion()" class="form-control" id>
                        <option value="yes">Yes</option>
                        <option value="no">No</option>
                        <option value="regularly">Regularly</option>
                        <option value="sometimes">Sometimes</option>
                    </select>


            </div>


@endforeach

</form>

_fixture.Inject(new ControllerContext());

当用户选择ID为1和2的问题时，我希望输出“您需要学习更多”。

Answer 1

使用以下命令更新您的javascript函数：

    function sendSuggestion() {
    if (document.getElementById("1").value == "no" && document.getElementById("2").value == "no"  ){
        if (suggestions.indexOf("you need to study more") == -1){
            suggestions.push("you need to study more");
        }
    }

    if (document.getElementById("1").value == "yes" && document.getElementById("2").value == "yes"  ){
        var index = suggestions.indexOf("you need to study more");

        if (index > -1) {
           suggestions.splice(index, 1);
        }
    }
}

这将在您的数组中提供不同的建议，而不重复。

Answer 2

如果您不需要存储多个建议，则可以在每次函数调用时将数组设置为空。

var suggestions=[];

function sendSuggestion() {
    // here will work
    suggestions = [];
    if (document.getElementById("1").value == "no" && document.getElementById("2").value == "no") {
        // or if you only want to set to empty if the conditional passes you can do it here
        suggestions = [];
        suggestions.push("you need to study more");
     }
}

如果需要或要填充阵列，可以检查特定项目。无需在条件数组中重新初始化数组，而是运行此命令

let index = suggestions.indexOf("you need to study more");
// negative one is returned if the item is not found
// if it's found we'll remove it from the array
if (index > -1) suggestions.splice(index, 1);

文档//

Array.splice（）-https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/splice

Array.indexOf（）-https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf

在数组中保存多个下拉选项

2 个答案: