addEventListener click

Question

我在这一点上开始了一些初学者教程，点击数字按钮后屏幕应该会改变，但一直是0。工作了几个小时。我应该在哪里查找错误的一些提示？

let buffer = "0";

const screen = document.querySelector(".screen");
document
.querySelector(".calc-buttons")
.addEventListener("click", function(event) {
buttonClick(event.target.innerText);
});
function buttonClick(value) {
if (isNaN(parseInt(value))){
handleSymbol(value);
} else {
handleNumber(value);
}
}

function handleNumber(value){

if (buffer === "0"){
buffer = value;
} else {
buffer += value;
}
rerender();
}
function handleSymbol(value){
}
function rerender() {
screen.innerText = buffer;
}

Answer 1

适用于我的

let buffer = "0";

const screen = document.querySelector(".screen");
document
.querySelector(".calc-buttons")
.addEventListener("click", function(event) {
buttonClick(event.target.innerText);
});
function buttonClick(value) {
if (isNaN(parseInt(value))){
handleSymbol(value);
} else {
handleNumber(value);
}
}

function handleNumber(value){

if (buffer === "0"){
buffer = value;
} else {
buffer += value;
}
rerender();
}
function handleSymbol(value){
}
function rerender() {
screen.innerText = buffer;
}

<div class="screen"></div>
<div class="calc-buttons">
<button>1</button>
</div>