What is the difference between type assertions and type guards in TypeScript?

What is the difference between type assertions and type guards in TypeScript?

Type assertions are a way to tell the TypeScript compiler to treat a value as a specific type, while type guards are runtime checks that ensure a value is of a certain type.

Can you give me an example of type assertions?

Sure! You can use type assertions like this: let someValue: any = 'this is a string'; let strLength: number = (someValue as string).length;

And how about type guards?

Type guards can be implemented using the typeof operator. For example: if (typeof someValue === 'string') { console.log(someValue.length); } This checks if someValue is a string before accessing its length.

When should I use type assertions instead of type guards?

Use type assertions when you're certain about the type and want to bypass TypeScript's checks. Use type guards for safer runtime type checking.