length 예제
<iframe src="https://homzzang.com/b/html"></iframe>
<iframe src="https://homzzang.com/b/css"></iframe>
<iframe src="https://homzzang.com/b/js"></iframe>
<button onclick="homzzang()">클릭</button>
<p id="demo"></p>
<script>
function homzzang() {
var x = window.length;
document.getElementById("demo").innerHTML = x;
}
</script>
결과보기
결과값: 3