单击选项后如何添加新的选择菜单
我正在尝试复制此页面
https://arrayexplorer.netlify.com/
最好的方法是什么？ 因为这是重复的，我不想每个人都手动出来
我的第一种方法是获取值字符串，并在值名称上设置一个数组并循环遍历，但是该函数将值作为字符串而不是变量，然后我尝试了一个 switch 语句，这将是长篇大论。
var addItems = ['elements to an array', 'elements at the end'];
var test = ['test', 'hhh'];
var secondOption = document.getElementById('secondOption');
//secondselect
menu
var arrOptions = document.querySelector('.arrOptions'); //select menu
arrOptions.addEventListener('change', (e) => {
var arrValue = e.target.value;
switch (arrValue) {
case 'addItems':
secondOption.innerHTML = '';
runValues(addItems);
break;
case 'other':
secondOption.innerHTML = '';
runValues(test);
break;
}
});
function runValues(arr) {
console.log(typeof arr);
for (var i = 0; i < arr.length; i++) {
secondOption.innerHTML += '<option>' + arr[i] + '</option>';
}
}
//html
<select class="arrOptions">
<option value="addItems">Add Items to an Array</option>
<option value="removeItem">Remove Items</option>
<option value="findItems">Find Items</option>
<option value="walkOver">Walk Over Items</option>
<option value="returnString">Return a String</option>
<option value="orderArray">Walk Over Items</option>|
<option value="other">Other</option>
</select>
繁华开满天机2回答
-
GCT1015
这并不完美，但它是如何动态更改<select>元素中的选项的示例。更新了 codepen 示例。HTML：<html> <button id='button' onClick='handleClick()'>Change Array</button> <input type='number' id='number' value='0' onChange='handleChange()'/> <select id='select'> </select></html>JavaScript：const lists = [ { one: { value: 1 }, two: { value: 2 }, three: { value: 3} }, { four: { value: 4 }, five: { value: 5 }, six: { value: 6} }, { seven: { value: 7 }, eight: { value: 8 }, nine: { value: 9 } }]const inputNumber = document.getElementById('number')const select = document.getElementById('select')function handleClick() { inputNumber.value = parseInt(inputNumber.value) + 1 handleChange()}function handleChange() { select.innerHTML = '' // Removes previous list options on update const currentNumber = parseInt(inputNumber.value) const currentList = lists[currentNumber - 1] const keys = Object.keys(currentList) keys.map((key, index) => { const newOption = document.createElement('option') newOption.value = currentList[key].value newOption.innerHTML = key select.appendChild(newOption) })} -
侃侃无极
There are two function one for which option is selected and according selected value switch call second function named runValues(array) with parameter as array and set option in second select box. copy script and html code and paste in your code necessary place and check and verify.<script>var addItems = ['elements to an array', 'elements at the end'];var test = ['test', 'hhh'];var arrFindItems = ['milk', 'eggs', 'sugar', 'keys']; function event_function() { var select_one = document.getElementById("select_one"); var selected_option = select_one.options[select_one.selectedIndex]; switch(selected_option.value) { case "addItems" : runValues(addItems); break; case "removeItem" : runValues(test); break; case "findItems" : runValues(arrFindItems); break; } } function runValues(arr) { var secondOption = document.getElementById('second_select'); secondOption.innerHTML = ""; alert("First Element of Array : " + arr[0]); for (var i = 0; i < arr.length; i++) { secondOption.innerHTML += '<option>' + arr[i] + '</option>'; } }//Html File<html><body>I Have An Array :<select class="arrOptions" id="select_one" onchange="event_function()"> <option value="addItems">Add Items to an Array</option> <option value="removeItem">Remove Items</option> <option value="findItems">Find Items</option> <option value="walkOver">Walk Over Items</option> <option value="returnString">Return a String</option> <option value="orderArray">Walk Over Items</option>| <option value="other">Other</option></select>I m interested in :<select id="second_select"></select></body></html>
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相关分类
JavaScript