[Global] JS - undefined 속성 - 정의안됨 (= 미정의) [전역속성]

undefined 예제

 

<button onclick="homzzang()">클릭</button>

<p id="demo"></p>

<script>

function homzzang() {

  var Hz;

  if (typeof Hz === "undefined") {

    txt = "Hz is undefined";

  } else {

    txt = "Hz is defined";

  }

  document.getElementById("demo").innerHTML = txt;

}

</script>

 

결과보기

결과값: Hz is undefined