操作符用于在JavaScript中检查属性是否存在于对象中。
您可以尝试运行以下代码以了解如何在JavaScript中使用in操作符−
实时演示
<!DOCTYPE html>
<html>
<body>
<script>
var emp = {name:"Amit", subject:"Java"};
document.write("name" in emp);
document.write("<br>");
document.write("subject" in emp);
document.write("<br>");
document.write("MAX_VALUE" in Number);
document.write("<br>");
document.write("MIN" in Number);
</script>
</body>
</html>
