javascript - 根据文本输入更改具有特定类的所有元素

Question

我认为这将是非常简单的事情，但我还没有找到答案。我如何让所有带有 class="namehere" 的 span 元素显示输入文本中插入的内容？

function start() {
  var name = document.getElementById("name").value;
  document.getElementByClassName("namehere").innerHTML = name;
}

<input id="name" type="text" value="Type name here">
<button type="button" onclick="start()">start</button>
<br>
<br>
<span class="namehere"></span> is doing this and that.
<br>
<span class="namehere"></span> wants to do this and that.
<br>
<span class="namehere"></span> is not doing this or that.
<br>
<span class="namehere"></span> wants to do this but instead is doing that.

Answer 1

method getElementsByClassName()返回类似数组的元素对象。

您需要遍历每个元素并通过其索引访问它。

Working Example

var nameElements = document.getElementsByClassName('namehere');
for (var i = 0; i < nameElements.length; i++) {
    nameElements[i].textContent = document.getElementById('name').value;
}

或:

var nameElements = document.getElementsByClassName('namehere');
Array.prototype.forEach.call(nameElements, function (el) {
    el.textContent = document.getElementById('name').value;
});