i'm trying to do a multiple choice question that when selected the right answer enable a button
function enAble() {
let possibleAns = document.getElementById('question').value;
if (possibleAns != 1) {
document.getElementById("btton").disabled = true;
} else if (possibleAns = 1) {
document.getElementById("btton").disabled = false;
}
}<select id="question" onchange="enAble()">
<option>wrong answer</option>
<option value="1">right answer</option>
<option>wrong answer</option>
</select>
<button id="btton" type="button" disabled>button</button>uj5u.com熱心網友回復：
在else if (possibleAns = 1) {，(possibleAns = 1)是一個賦值陳述句。用于else if (possibleAns == 1) {檢查是否相等。
uj5u.com熱心網友回復：
將 possibleAns !=1 更改為 possibleAns !==1
在 else 陳述句中也使用 possibleAns ===1
uj5u.com熱心網友回復：
一種最簡潔的編碼方式（恕我直言）。
const
select_element = document.getElementById('question')
, button_element = document.getElementById("btton")
;
select_element.onchange = () =>
{
button_element.disabled = (select_element.value != '1')
}<select id="question">
<option value="0">wrong answer</option>
<option value="1">right answer</option>
<option value="2">wrong answer</option>
</select>
<button id="btton" type="button" disabled>
button
</button>轉載請註明出處，本文鏈接：https://www.uj5u.com/caozuo/487474.html
標籤：javascript html 按钮 选择 改变