Question

这是我的代码：

<script type="text/javascript">

var index = -1;
var memo = ['num1','num2','num3','num4','num5','num6'];



function start() {

index = (index + 1) % memo.length ;

var cusid_ele = document.getElementsByClassName('MemoClass');

for (var i = 0; i < cusid_ele.length; ++i) { var item = cusid_ele[i]; item.innerHTML = memo[index]; }

}
</script>

<input type="button" value="start" onclick="start()">
</br>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>

当您按下开始按钮时

每个类名都有一个重复值，我希望这些值有序地给出，这样在按START时输出： num1 num2 num3 num4 num5 num6

Answer 1

因为您的索引未循环更改，所以从memo[index]更改为memo[i];

for (var i = 0; i < cusid_ele.length; ++i) { var item = cusid_ele[i]; item.innerHTML = memo[i]; }
}

<script type="text/javascript">

var index = -1;
var memo = ['num1','num2','num3','num4','num5','num6'];



function start() {

index = (index + 1) % memo.length ;

var cusid_ele = document.getElementsByClassName('MemoClass');

for (var i = 0; i < cusid_ele.length; ++i) { var item = cusid_ele[i]; item.innerHTML = memo[i]; }

}
</script>

<input type="button" value="start" onclick="start()">
</br>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>

Answer 2

您有错字

for (var i = 0; i < cusid_ele.length; ++i) { var item = cusid_ele[i]; item.innerHTML = memo[i]; // here change from index to i
}

一种更好的方法是将每个跨度和数组中的值一一对应，并将它们一一放置

var memo = ['num1', 'num2', 'num3', 'num4', 'num5', 'num6'];
let allspans = document.querySelectorAll('.MemoClass'); // all the spans in an array

function start() {
  memo.forEach((a, post) => allspans[post].innerHTML = a) // for every value in the array, put the innerHTML of every class 
}

span {
  color: red;
}

<input type="button" value="start" onclick="start()">
</br>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>
</br>
<span class="MemoClass"></span>

Answer 3

将备忘录[index]更改为备忘录[i]，所以您拥有

for (var i = 0; i < cusid_ele.length; ++i) { var item = cusid_ele[i]; item.innerHTML = memo[i]; }

使用Javascript顺序更改所有类名称值

3 个答案: