What are type narrowing techniques in programming?

What are type narrowing techniques in programming?

Type narrowing techniques are methods used in programming to refine the type of a variable, allowing for more specific operations.

Can you give me an example of type narrowing in TypeScript?

Sure! In TypeScript, you can use the typeof operator to narrow down a variable's type. For example:

function example(value: string | number) {
    if (typeof value === 'string') {
        // Here, TypeScript knows 'value' is a string
        console.log(value.toUpperCase());
    }
}

Are there other ways to narrow types besides using typeof?

Yes, you can also use type guards, which are functions that return a boolean indicating whether a variable is of a specific type. For instance, you can create a custom type guard to check if an object is of a certain interface.

What are the benefits of using type narrowing?

The benefits include improved type safety, better code readability, and enhanced autocompletion features in IDEs, which help prevent runtime errors.