Method Calls

Method Calls

Finally, let’s use our new methods to access and manipulate data from Dog instances.

 

class Dog { 
	constructor(name) { 
    	this._name = name; 
        this._behavior = 0; 
    } 
    
    get name() { 
    	return this._name; 
    } 
    
    get behavior() { 
    	return this._behavior; 
    } 
    
    incrementBehavior() { 
    	this._behavior++; 
    } 
} 

const halley = new Dog('Halley');

 

In the example above, we create the Dog class, then create an instance, and save it to a variable named halley.

The syntax for calling methods and getters on an instance is the same as calling them on an object — append the instance with a period, then the property or method name. For methods, you must also include opening and closing parentheses.

Let’s take a moment to create two Dog instances and call our .incrementBehavior() method on one of them.

 

let nikko = new Dog('Nikko'); // Create dog named Nikko
nikko.incrementBehavior(); // Add 1 to nikko instance's behavior 
let bradford = new Dog('Bradford'); // Create dog name Bradford 
console.log(nikko.behavior); // Logs 1 to the console 
console.log(bradford.behavior); // Logs 0 to the console

 

In the example above, we create two new Dog instances, nikko and bradford. Because we increment the behavior of our nikko instance, but not bradford, accessing nikko.behavior returns 1 and accessing bradford.behavior returns 0.

 

---

class Surgeon {
  constructor(name, department) {
    this._name = name;
    this._department = department;
    this._remainingVacationDays = 20;
  }
  
  get name() {
    return this._name;
  }
  
  get department() {
    return this._department;
  }
  
  get remainingVacationDays() {
    return this._remainingVacationDays;
  }
  
  takeVacationDays(daysOff) {
    this._remainingVacationDays -= daysOff;
  }
}

const surgeonCurry = new Surgeon('Curry', 'Cardiovascular');
const surgeonDurant = new Surgeon('Durant', 'Orthopedics');

console.log(surgeonCurry.name);
surgeonCurry.takeVacationDays(3);
console.log(surgeonCurry.remainingVacationDays);