javascript - 如何使用javascript将一个字段输入值复制到另一字段输入

Question

想要在有人单击复选框时将某些字段从我的表单复制到另一个字段，并在取消选中复选框时将其删除。

我是怎么做到的，但它不起作用。

<script>
function filladdress(f) {
  if(f.sameaddress.checked == true) {
    f.present_address1.value = f.perm_address1.value;
    f.present_address2.value = f.perm_address2.value;
    f.present_address3.value = f.perm_address3.value;
  }
}
</script>

这是表格..

<form name="OnlineForm" method="post" onsubmit="return OnSubmitForm();" action="apply4.php">
<input name="present_address1" type="text" title="Maximum 35 Character allowed" class="textBoxDashed" id="present_address1" value="" size="43"  maxlength="35">
<input name="present_address2" type="text" title="Maximum 35 Character allowed" class="textBoxDashed" id="present_address2" value="" size="43" maxlength="35">
<input name="present_address3" title="Maximum 35 Character allowed" class="textBoxDashed" id="present_address3" value="" size="43" maxlength="35">

<input type="checkbox" name="sameaddress" onclick="filladdress(this.OnlineForm)">

<input name="perm_address1" type="text" title="Maximum 35 Character allowed" class="textBoxDashed" id="perm_address1" value="" size="43" maxlength="35">
<input name="perm_address2" type="text" title="Maximum 35 Character allowed" class="textBoxDashed" id="perm_address2" value="" size="43" maxlength="35">
<input name="perm_address3" type="text" title="Maximum 35 Character allowed" class="textBoxDashed" id="perm_address3" value="" size="43" maxlength="35">

Answer 1

当复选框单击时，在 html 中使用 document 代替 this

您将通过 this.OnlineForm 获得未定义的传递

请参阅此处演示 https://jsbin.com/subebaz/edit?html,js,output

并在复制功能中切换赋值顺序