Multiple ways to declare a function on a TypeScript interface: how are they different? -

i've seen properties functions declared in multiple ways, illustrated func1 , func2 on typescript interface:

interface thing {     func: (arg:string) => number;     func2(arg:string): number; } 

is there difference between two? there case in use 1 on other?

this playground link seems imply 2 can used interchangeably. there limits this?

is there difference between two

yes.

func: (arg:string) => number;

this version means property. limit when try declare overloads.

func2(arg:string): number;

this preferred functions means can declare overloads after fact (using open ended nature of interfaces)

seems imply 2 can used interchangeably

that because type compatible. not mean they same thing. see property vs. method below:

example

this should clarify :

interface thing {     func: (arg: string) => number;     func2(arg:string): number; }  interface thing {     // overload not permitted     func: (arg: number) => string; // error!     // overload okay      func2(arg: number): string; }