Step 9: Objects

Now for the final data type: objects. Like arrays, they can store multiple bits of information, except objects store the properties of something. For example, you might want to save the name, model and colour of a car. Or the name, time and location of a film playing at the cinema.

The syntax looks like this:

{  property1: "value1",  property2: "value2",  property3: "value3" }

The names on the left ("property1") are known "keys". You can call them whatever you want, and any values can be given to them: strings, booleans, integers.

Try it out

Let's define an object that represents a person:

var person = {  
  firstName: "Virginia",  
  lastName: "Woolf",  
  occupation: "writer",  
  age: 59,  
  alive: false
};

We can of course console.log() the entire object, but you can also reference just one of the properties. Run this code:

console.log(person.firstName);

Mini challenge

Using an object representing a person, console.log() a sentence introducing the person. Print out the following:

"Hi, my name is {firstName} {lastName}. I am {age} years old, and work as a {occupation}."

Hint: you can construct a string by adding different strings and values together using the concatenation operator +. This includes the keys and values of objects. For example:

var animal = {    
  species: "cat",     
  name: "Tabitha"
};

console.log("My " + animal.species + "is called " + animal.name + ".");

Don't forget, you might need to include spaces.