Creating a strongly-typed array
We will learn how to create strongly-typed arrays at the start of this lesson. We will use two different methods to achieve this before learning how to create strongly-typed rest parameters.
Arrays can hold mixed value types #
Before we learn how to create a strongly-typed array, let’s look at an array that has been declared without a type annotation. The code below constructs an array containing three different values, each with a different type.
const items = [];items.push(1);items.push("two"),items.push(false);console.log(items);
Why doesn’t the code above raise a type error?
Using the Array generic type #
We can use a type annotation to specify that an array should only contain items of a specific type. There is an Array generic type that we can use to do this. We pass ...