typescript - Function property vs method

Question

What practical differences are there between defining an interface method:

interface Foo {
    bar(): void;
}

and defining a property with a function type:

interface Foo {
    bar: () => void;
}

?

Answer 1

If these are the only declarations, these are identical.

The only difference is that you can augment the first form in a second declaration to add new signatures:

// Somewhere
interface Foo {
  bar(): void;
}

// Somewhere else
interface Foo {
  bar(s: number): void;
}

// Elsewhere
let x: Foo = ...
x.bar(32); // OK