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Using TypeScript with React

Understanding the types in JavaScript

Explore the fundamental types available in JavaScript and understand its loose typing nature. Learn how JavaScript handles various primitive types like string, number, boolean, bigint, null, undefined, and symbol. This lesson highlights JavaScript's lack of strict type enforcement, setting the stage for introducing TypeScript's strong typing features to improve development robustness.

We'll cover the following...

Primitive types in JavaScript #

JavaScript does have some basic primitive types, but what are they?

The JavaScript code below outputs the types of four variables with various kinds of values. We’d hope for string, number, boolean, and date to be output … but is this the case? Run the code and find out.

Javascript (babel-node)
const name = "Bob";
console.log("Type of name:", typeof name);
const age = 30;
console.log("Type of age:", typeof age);
const cool = true;
console.log("Type of cool:", typeof cool);
const dateOfBirth = new Date(1989, 10, 5);
console.log("Type of dateOfBirth:", typeof dateOfBirth);

Nearly! JavaScript does ...