JavaScript 中的松散相等

javascriptweb developmentobject oriented programming更新于 2025/9/3 5:00:17

松散相等运算符"=="允许我们通过先将两个或多个操作数的值转换为通用类型，然后检查它们之间的相等性来比较它们。

以下是在 JavaScript 中实现松散相等的代码 −

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>Loose equality in JavaScript.</h1>
<div class="result"></div>
<br />
<button class="btn">点击此处</button>
<h3>Click on the above button see some comparisons using loose equality</h3>
<script>
   let resEle = document.querySelector(".result");
   let BtnEle = document.querySelector(".Btn");
   BtnEle.addEventListener("click", () => {
      resEle.innerHTML = "According to loose equality <br>";
      if (1 == "1") {
         resEle.innerHTML += "1 is equal to '1'<br>";
      }
      if (undefined == null) {
         resEle.innerHTML += "undefined is equal to null <br>";
      }
   });
</script>
</body>
</html>