Hi i have had this question while i was learning the basics of typescripts, i have asked the question on stackoverflow.
https://stackoverflow.com/q/75343408/16057454
#Typescript does not seem to restrict the parameters passed in a constructor
humble musk
unkempt heath
@humble musk What would be the point of interfaces if every property of the class had to appear on the interface?
The point of implementing an interface - though there's actually fairly little reason to do so - is to say "the class must have at least these properties.
Anything that has a format() method that can be called without arguments and returns a string is a valid HasFormmater. (It doesn't even have to be a class, or use implements HasFormatter - unlike Java)
This may be helpful: https://www.typescriptlang.org/play#example/structural-typing
humble musk
<@710022314640539730> What would be the point of interfaces if every property of...
@unkempt heath if we define any interface and have an object
const obj1:interface1;
obj1 cannot have any additional property that are not mentioned in the interface.
@unkempt heath see the above codesnippet
thick summit
that is only a requirement in the context of literals
median inletBOT
interface Foo {
foo: string;
}
// error because we are constructing a literal value on the RHS
const foo1: Foo = { foo: "", bar: 1 };
// ^^^^^^
// Type '{ foo: string; bar: number; }' is not assignable to type 'Foo'.
// Object literal may only specify known properties, and 'bar' does not exist in type 'Foo'.
// implictly has the type { foo: "", bar: 1 }
const foo2 = { foo: "", bar: 1 };
// no error, `foo2` is assignable to `Foo`
const foo3: Foo = foo2;