The constructor method in JavaScript is used to create and initialize object created within a class. If a constructor method is not added, then a default constructor should be used.
Note − Only one occurrence of a constructor method is allowed in a class. More than one throws an error.
Example
You can try to run the following code to learn how to implement a constructor method
Live Demo
<html>
<body>
<script>
class Department {
constructor() {
this.name = "Department";
}
}
class Employee extends Department {
constructor() {
super();
}
}
class Company {}
Object.setPrototypeOf(Employee.prototype, Company.prototype);
document.write("<br>"+Object.getPrototypeOf(Employee.prototype) === Department.prototype);
let myInstance = new Employee();
document.write("<br>"+myInstance.name);
</script>
</body>
</html>