如何通过javascript更新html自定义按钮输入中的子属性

Question

I want to update data-percent value on a radiobutton click before clicking the update button

html:

<input type="radio" name="percentage" value="50" onclick="changeVal(this.value)"> Happy 50 percent</input>

</br>

<input type="radio" name="percentage" value="75" onclick="changeVal(this.value)"> Happy 75 percent</input>
</br>

<button class="btn btn-danger my-btn" id = "myUpdateBtn" data-id="1" data-name="John" data-summary="John is Happy" data-percent="50" >Click to Update</button>

javascript: my script function does not update button sub attribute value. please help.

changeVal(val){
 alert(val);
 document.getElementById("myUpdateBtn").value('data-price') = val;
}

Answer 1

In order to access data attributes you have to do it like this:

 var val = document.getElementById('21').dataset.id; var msg = document.getElementById('21').dataset.name; alert(val); //Alert '21' alert(msg); //Alert 'HiDiv' document.getElementById('21').dataset.lastName = 'Rod'; //Create new data attribute console.log(document.getElementById('21')); //View changes 

 <div data-id='21' id='21' data-name = 'HiDiv'> </div>