Question

我想通过点击添加按钮，使用下面的javascript动态地将表单输入字段添加到表单中：

var i = 0;
function increment() {
i += 1;
}

function addfieldFunction() {
    var r = document.createElement('div');
    var y = document.createElement("INPUT");
    var z = document.createElement("INPUT");
    y.setAttribute("class", "dash-input");
    y.setAttribute("type", "text");
    y.setAttribute("placeholder", "University");
    z.setAttribute("class", "dash-input");
    z.setAttribute("type", "text");
    z.setAttribute("placeholder", "Course");
    increment();
    y.setAttribute("Name", "a_level[ + i ][0]");
    r.appendChild(y);
    z.setAttribute("Name", "a_level[ + i ][1]");
    r.appendChild(z);
    document.getElementById("form-div").appendChild(r);
}



<form class = "dash-form" method = "POST" action = "/" >
     <div id = "form-div">
         <input class = "dash-input" type = "text" name = "a_level[+i][0]" value = "" placeholder = "University"/>
         <input class = "dash-input" type = "text" name = "a_level[+i][1]" value = "" placeholder = "Course"/>
     </div>
     <div class = "dash-submit">
        <input class = "dash-submit-button" type = "submit" value = "Submit"/>
    </div>
</form>
<div class = "dash-add">
    <button class = "dash-add-button" onclick = "addfieldFunction()">ADD</button>
</div>

该函数返回 i ，而不是递增并返回一个整数，如下所示：

<div id = "form-div">
    <input class = "dash-input" type = "text" name = "a_level[0][0]" value = "" placeholder = "University"/>
    <input class = "dash-input" type = "text" name = "a_level[0][1]" value = "" placeholder = "Course"/>
</div>

Answer 1

使用i运算符

连接变量+(concatenation operator)

concatenation operator (+)将两个字符串值连接在一起，返回另一个字符串，即两个操作数字符串的union。

＆＃13;

var i = 0;

function increment() {
  i += 1;
}

function addfieldFunction() {
  var r = document.createElement('div');
  var y = document.createElement("INPUT");
  var z = document.createElement("INPUT");
  y.setAttribute("class", "dash-input");
  y.setAttribute("type", "text");
  y.setAttribute("placeholder", "University");
  z.setAttribute("class", "dash-input");
  z.setAttribute("type", "text");
  z.setAttribute("placeholder", "Course");
  increment();
  y.setAttribute("name", "a_level[ " + i + " ][0]"); //Keep attribute in lower case
  r.appendChild(y);
  z.setAttribute("name", "a_level[ " + i + "][1]");
  r.appendChild(z);
  document.getElementById("form-div").appendChild(r);
}

＆＃13;

<form class="dash-form" method="POST" action="/">
  <div id="form-div">
    <input class="dash-input" type="text" name="a_level[+i][0]" value="" placeholder="University" />
    <input class="dash-input" type="text" name="a_level[+i][1]" value="" placeholder="Course" />
  </div>
  <div class="dash-submit">
    <input class="dash-submit-button" type="submit" value="Submit" />
  </div>
</form>
<div class="dash-add">
  <button class="dash-add-button" onclick="addfieldFunction()">ADD</button>
</div>

＆＃13;

Answer 2

你需要像这样连接它：

y.setAttribute("name", "a_level[" + i +"][0]");

正如Rayon指出的那样：尽管HTML5标准不需要小写属性名称，但保持属性为小写（参见here）。 W3C推荐它，但XHTML验证将使用大写字母失败。

将输入字段添加到HTML表单

2 个答案: