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Learn TypeScript: The Complete Course for Beginners

Introduction to TypeScript's Many Objects

Explore the different object types in TypeScript including Object versus object and the role of curly braces. Learn to distinguish these forms and understand how non-primitive types are represented through class instantiation and Object.create in this lesson.

We'll cover the following...

TypeScript has many different object types.

In this section, we will see the difference between the two objects which are confusingly called Object and object – one that starts with an uppercase O and another with a lowercase o.

TypeScript 3.3.4
let o1: Object = "I am an Object";
let o2: object = { text: "I am an object" };
let o3: Object = { text: "I am also an Object" }
let o4: object = ["I", "am", "an", "object"];
let o5: Object = ["I", "am", "an", "Object"];
console.log(o1);
// console.log(o2.text); // Does not compile
// console.log(o3.text); // Does not compile
console.log(o4);
console.log(o5);

We will also see how the curly bracket brings a third object type.

TypeScript 3.3.4
let curly1 = { text: "An object" };
let curly2: { text: string } = { text: "An object" };
let curly3: {} = { text: "An object" };
console.log(curly1.text);
console.log(curly2.text);
// console.log(curly3.text); // Does not not compile

The lowercase object comes not only from Object.create, but also if you instantiate a class in TypeScript. It represents all types that are not primitive, which means those that are not Boolean, number, string, symbol, null, or undefined.

TypeScript 3.3.4
let create1 = Object.create({ text: "I am a created object" });

let p = { text: "I am an object" };

let create2 = Object.create(p);



console.log(create1.text);

console.log(p.text);

console.log(create2.text);

In the upcoming lesson, we’ll study the curly braces object in more detail.