我想在我的按钮的值字段中添加一个JS变量echo

Question

我希望echo button's value field中的{capnum}值<script type="text/javascript"> var capnum = 0; function add() { capnum++; document.getElementById('display').innerHTML = capnum; } </script> <button name="subject" type="submit" value="<script> document.write(capnum) </script>" onclick="showUser(this.value);add()" >NEXT</button> ...我该怎么做？ 我的代码在这里 -

SELECT 1=1 

Answer 1

试试这个，

 <script type="text/javascript">
 var capnum = 0;
 function add()
 {
    capnum++;
     document.getElementById('display').innerHTML = capnum;
 }
 </script>

 <button id="display" name="subject" type="submit" value="<script> document.write(capnum) </script>" onclick="showUser(this.value);add()" >NEXT</button>

Answer 2

只需添加id =＆＃34;显示＆＃34;到你的按钮。 我还将.innerHTML更改为.value，因为您的帖子表示您想要更改其值。

<script type="text/javascript">
    var capnum = 0;

    function add()
    {
     capnum++;
     document.getElementById('display').value = capnum;
    }

    function showUser(i) { // i just added this to test if value was changing
        alert(i);
    }
</script>

<button id="display" name="subject" type="submit" value="" onclick="add(); showUser(this.value);" >NEXT</button>

当我测试确保它有效时，我也在add（）之后移动了showUser

Answer 3

setAttribute javascript

的属性

<button name="subject" id="myId"  type="submit"  onclick="add(this.value);add()" >NEXT</button>
<script type="text/javascript">
var capnum = 0;
function add()
{
capnum++;
 document.getElementById('myId').setAttribute('value', capnum);  
}

</script>