Class, object, property and method
Name:
Date:
Class:
A
Quick Questions
Shade in the A or B circle for each question.
1. In class Dog, which statement is correct?
2. Which one is a property of a Dog object?
3. Which one is a method of a Dog object?
4. How many Dog objects can you make from one Dog class?
5. Which sentence matches the idea of properties and methods?
B
Match the Pairs
Draw a line connecting each item on the left to its match on the right.
| Left column | Right column | |
|---|---|---|
| 1class Dog { } | AThe new keyword is missing, so no object is made from the class. It should be new Dog("Rex"). | |
| 2let rex = new Dog("Rex"); | Bbark is a method of a dog object, not of the class blueprint. Make an object like rex first, then call rex.bark(). | |
| 3A property holds data about an object, like a noun (the dog's name) | CA blueprint that describes what every dog will have and do | |
| 4A method is an action an object can do, like a verb (bark) | Dconsole.log(rex.name); | |
| 5Dog.bark(); | Erex.bark(); | |
| 6let rex = Dog("Rex"); | FMakes one object, the dog Rex, from the Dog blueprint |
C
Definitions
class Dog
D
Fill in the Blanks
Complete each line of code by filling in the missing parts.
1.
_____ Dog {
bark() { console.log("Woof!"); }
}
2.
const rex = new ___("Rex");
3.
const rex = new Dog("Rex");
console.log(rex.____);
4.
const rex = new Dog("Rex");
rex.____();
5.
constructor(name) {
____.name = name;
}
E
Spot the Error
Shade in the letter of the line that contains an error.
Question 1
A
class Dog {
B
constructor(name) {
C
name = name;
D
}
E
}
Question 2
A
class Dog {
B
bark() {
C
console.log('Woof!';
D
}
E
}
Question 3
A
class Dog {
B
constructor(name, age) {
C
this.name = name;
D
this.age = name;
E
}
F
}
Question 4
A
class Dog {
B
function bark() {
C
return 'Woof!';
D
}
E
}
Question 5
A
class Dog {
B
construct(name) {
C
this.name = name;
D
}
E
}
Answer Key
Class, object, property and method
Section A: Quick Questions
Q1
B — Dog is the blueprint and Rex is one object made from it
Q2
A — name
Q3
A — bark()
Q4
B — As many as you need, such as Rex and Bella
Q5
A — Properties are nouns that hold data and methods are verbs that act
Section B: Match the Pairs
Q1
class Dog { } → A blueprint that describes what every dog will have and do
Q2
let rex = new Dog("Rex"); → Makes one object, the dog Rex, from the Dog blueprint
Q3
A property holds data about an object, like a noun (the dog's name) → console.log(rex.name);
Q4
A method is an action an object can do, like a verb (bark) → rex.bark();
Q5
Dog.bark(); → bark is a method of a dog object, not of the class blueprint. Make an object like rex first, then call rex.bark().
Q6
let rex = Dog("Rex"); → The new keyword is missing, so no object is made from the class. It should be new Dog("Rex").
Section C: Definitions
Q1
class Dog — A blueprint for dogs. An object like Rex is made from it. Properties are its data (nouns like name) and methods are its actions (verbs like bark).Section D: Fill in the Blanks
Q1
class Dog {
bark() { console.log("Woof!"); }
}Q2
const rex = new Dog("Rex");Q3
const rex = new Dog("Rex");
console.log(rex.name);Q4
const rex = new Dog("Rex");
rex.bark();Q5
constructor(name) {
this.name = name;
}Section E: Spot the Error
Q1
C — A property belongs to the object, so it must be set with this. The line should be this.name = name; otherwise the dog never gets a name property.
Q2
C — The closing bracket of console.log is missing. The method body should say console.log('Woof!');
Q3
D — The age property is being given the name value. It should be this.age = age; so each property stores its own data.
Q4
B — Methods inside a class are written without the function keyword. The line should be bark() {
Q5
B — The special method that builds each object must be called constructor, not construct. It should be constructor(name) {