在 JavaScript 中使用閉包實現私有屬性

以下是使用閉包在 JavaScript 中實現私有屬性的程式碼 −

示例

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Document</title>
<style>
   body {
      font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
   }
   .result {
      font-size: 20px;
      font-weight: 500;
      color: blueviolet;
   }
</style>
</head>
<body>
<h1>Private properties, using closures</h1>
<div class="result">0</div>
<br />
<button class="Btn">CLICK HERE</button>
<h3>Click on the above button to increment the above counter using closures</h3>
<script>
   let BtnEle = document.querySelector(".Btn");
   let resEle = document.querySelector(".result");
   function test() {
      let a = 0;
      return function incrementA() {
         a++;
         return a;
      };
   }
   let storeVal = test();
   BtnEle.addEventListener("click", (event) => {
      resEle.innerHTML = storeVal();
   });
</script>
</body>
</html>