如何使用计数器更改div值

Question

我不明白为什么每次按下按钮时这个函数都不更改num的值。基本上，我想做一个计数器，每次按下按钮都会向div添加一个。

<div class="elements" id="txtthrow">0</div>
<button class="button1" id="buttonNewHand" onclick="newFaceTot()">new<br>number</button>

//------------------------------------------------------------------------

refthrow = document.getElementById("txtthrow");

function newFaceTot(){
numberChanged();
}
function numberChanged(){
var num = parseInt(refthrow.value, 10);
refthrow.innerHTML = changeNumber(num);
}
function changeNumber(num){
num = num + 1;
return num;
}

Answer 1

只有表单(例如input/select/textarea(元素才有值。对于其他元素，请使用innerHTML或innerText来获取内容。

const refthrow = document.getElementById("txtthrow");

function newFaceTot() {
numberChanged();
}
function numberChanged() {
var num = parseInt(refthrow.innerText, 10);
refthrow.innerHTML = changeNumber(num);
}
function changeNumber(num) {
num = num + 1;
return num;
}

<div class="elements" id="txtthrow">0</div>
<button class="button1" id="buttonNewHand" onclick="newFaceTot()">new<br>number</button>

因此，value属性为undefined。并且parseInt(undefined)是NaN(不是数字(。