<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>증감연산Javascript</title>
<style>
.display {
display: flex;
justify-content: center;
font-size: 300px;
}
.controller {
display: flex;
justify-content: center;
}
button {
width: 100px;
height: 50px;
}
</style>
</head>
<body>
<div class="display">0</div>
<div class="controller">
<button class="plus">+</button>
<button class="minus">-</button>
</div>
<script>
//querySelector : 태그에 해당하는 (id:#),(class:.),(tag) 값을 가져 올 수 있음
const display = document.querySelector(".display");
const plus = document.querySelector(".plus");
const minus = document.querySelector(".minus");
console.log(display);
plus.addEventListener("click", function (event) {
//textContent : ?.물음표안에 텍스트 엘리먼트 값을 가져옴
display.textContent = +display.textContent + +1;
});
minus.addEventListener("click", function (event) {
display.textContent = +display.textContent - +1;
});
</script>
</body>
</html>
결과 화면
