使用其ID复制无线电值,以使用JavaScript将其作为值插入到输入中

Question

我有一些HTML代码如下:

<input name="bid" type="radio" value="1" id="1234"/>
<input name="bid" type="radio" value="2" id="5678"/>
<input type="text" id="paymount" name="paymount" value=""/>

所需功能:

当radio=1被选中时,paymount字段值将显示为1234.当radio=2被选中时,paymount字段值将显示为5678.

我在Stack Overflow上发现了帖子,但其中很多都与隐藏文本字段有关.

Answer 1

使用change事件处理程序来侦听事件.

// use `[].slice.call(document.querySelectorAll('[name="bid"]'))
// for older browser to covert NodeList to Array

// although check polyfill option of `ArrayforEach` for older browser
// or use simple `for` or `while` loop for iterating

// get all radio with the name,covert NodeList to array and iterate
Array.from(document.querySelectorAll('[name="bid"]')).forEach(function(ele) {
  // add event handler to the element
  ele.addEventListener('change', function() {
    // update value of the input element
    document.getElementById('paymount').value = this.id;
    // if you are used `data-id="value" attribute instead of `id`
    // then get the value using `this.dataset.id`
  });
});

<input name="bid" type="radio" value="1" id="1234" />
<input name="bid" type="radio" value="2" id="5678" />
<input type="text" id="paymount" name="paymount" value="" />

仅供参考:使用自定义data-*属性存储属性的相应值目的id是用于唯一标识元素. 可以从元素的属性中检索自定义 data-*属性值dataset.

Answer 2

<form name="radioForm">
    <input name="bid" type="radio" value="1" id="1234"/>
    <input name="bid" type="radio" value="2" id="5678"/>
    <input type="text" id="paymount" name="paymount" value=""/>
</form>     

<script type="text/javascript">
    var radio = document.radioForm.bid,
        input = document.getElementById('paymount');

    for(var i = 0; i < radio.length; i++) {
        radio[i].onclick = function() {            
            input.value = this.id;
        };
    }
</script>

的jsfiddle

Answer 3

我不确定这是否是最好的解决方案,但以下是您需要的工作.

var inputs = document.querySelectorAll('input[name="bid"]'),
    paymount = document.getElementById('paymount');

// loop over element, and add event listener
for (var i = 0; i < inputs.length; i++) {
  inputs[i].addEventListener("change", onChange);
}
// callback 
function onChange(){
  paymount.value = this.id; // change paymount value to the selected radio id
}

<input name="bid" type="radio" value="1" id="1234"/>
<input name="bid" type="radio" value="2" id="5678"/>
<input type="text" id="paymount" name="paymount" value=""/>