实现方式一：只在最后一个数据中动态添加或者删除

| 背景
需要做一个页面，页面可以输入参数，点击确认按钮可以发请求给某接口。但是接口的某个字段是数组类型，所以在页面上需要实现添加或者删除元素的功能。

| 实现
| html
前端是基于bootstrap4.0.

<form id="form" role="form" method="post" class="custom-control">
<div class="form-inline">
<label for="details" class="custom-control-label col-md-2">还款明细</label>
<button type="button" class="button btn-light" id="add-btn" οnclick="add_div()">添加明细</button>
<button type="button" class="button btn-light" id="del-btn" οnclick="del_div()">删除明细</button>
</div>
<div class="form-group" id="details">
<div class="form-inline">
<label for="receivable" class="custom-control-label col-md-3">应收金额</label>
<input type="text" class="form-control" id="receivable" value="" placeholder="应收金额 单位分"/>
</div>
<div class="form-inline">
<label for="period" class="custom-control-label col-md-3">还款期数</label>
<input type="text" class="form-control" id="period" value="" placeholder="还款期数"/>
</div>
<div class="form-inline">
<label for="kind" class="custom-control-label col-md-3">还款科目</label>
<input type="text" class="form-control" id="kind" value="" placeholder="还款科目"/>
</div>
</div>
</form>

|JS
<script type="text/javascript">
var detail_div = 1;
function add_div() {
var e = document.getElementById("details");
var div = document.createElement("div");
div.className = "form-group";
div.id = "details" + detail_div;
div.innerHTML = e.innerHTML;
document.getElementById("form").appendChild(div);
detail_div++;
}

function del_div() {
var id = "details" + (detail_div - 1).toString();
var e = document.getElementById(id);
document.getElementById("form").removeChild(e);
detail_div--;
}
</script>

效果
如图

实现方式二：只在最后一个数据中动态添加，删除任意一个节点

html代码

<form id="form" role="form" method="post" class="custom-control">    <div class="form-inline">        <label for="details" class="custom-control-label col-md-2">还款明细</label>        <button type="button" class="button btn-light" id="add-btn" οnclick="add_div()">添加明细</button>

    </div>    <div class="form-group" id="details">        <div class="form-inline" id="ddd">            <label for="receivable" class="custom-control-label col-md-3">应收金额</label>            <input type="text" class="form-control" id="receivable" value="" placeholder="应收金额 单位分"/>        </div>        <div class="form-inline">            <label for="period" class="custom-control-label col-md-3">还款期数</label>            <input type="text" class="form-control" id="period" value="" placeholder="还款期数"/>        </div>        <div class="form-inline">            <label for="kind" class="custom-control-label col-md-3">还款科目</label>            <input type="text" class="form-control" id="kind" value="" placeholder="还款科目"/>        </div>

        <hr style="border: 1px solid #f9c37b;width: 100%; margin-bottom: 10px;margin-top: 10px">

    </div></form>

js代码

<script type="text/javascript">    var detail_div = 1;    function add_div() {        debugger;        var e = document.getElementById("details");        var div = document.createElement("div");        div.className = "form-group";        div.id = "details" + detail_div;        div.innerHTML = e.innerHTML;

        var del = document.createElement('p')        del.innerHTML = '<button type="button" class="button btn-light" id="del-btn' + detail_div + '" οnclick="del_div(this.id)">删除明细</button>';        div.children.ddd.appendChild(del);        // div.getElementById('ddd').appendChild(del);

        // var bu = document.createElement('p')        //        //        // bu.innerHTML = '<button type="button" class="button btn-light" id="del-btn' + detail_div + '" οnclick="del_div(this.id)">删除明细</button>';        //        // // tr.innerHTML = '<td>'+data[i].name+'</td><td>'+data[i].age+'</td><td>'+data[i].sex+'</td><td><a href="javascript:;">修改</a>&nbsp;&nbsp;<a href="javascript:;">删除</a></td>'        // // document.getElementById('myBody').appendChild(tr)        //        // div.appendChild(bu);        // div.lastElementChild.id = "del-btn" + detail_div;        document.getElementById("form").appendChild(div);        detail_div++;    }

    function del_div(eleId) {        debugger;        var eeid = document.getElementById(eleId).parentNode.parentNode.parentNode.id;        var ee = document.getElementById(eeid);        document.getElementById("form").removeChild(ee);

        // var id = "details" + (detail_div - 1).toString();        // var e = document.getElementById(id);        // document.getElementById("form").removeChild(e);        // detail_div--;    }</script>