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

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

In TypeScript, type assertions are a way to tell the compiler to treat a value as a specific type, while type casting is more about converting a value from one type to another.

Can you give me an example of type assertions?

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

And how does type casting differ from that?

Type casting often involves using functions or methods to convert types, like Number('123') which converts a string to a number.

Are there any performance implications between the two?

Generally, type assertions do not affect performance since they are a compile-time feature, while type casting may involve runtime checks.