1# Function Overloads 2 3Many Web APIs are overloaded to take different types of arguments or to skip 4arguments completely. `web-sys` contains multiple bindings for these functions 5that each specialize to a particular overload and set of argument types. 6 7For example, [the `fetch` API][mdn-fetch] can be given a URL string, or a 8`Request` object, and it might also optionally be given a `RequestInit` options 9object. Therefore, we end up with these `web-sys` functions that all bind to the 10`window.fetch` function: 11 12* [`Window::fetch_with_str`](https://rustwasm.github.io/wasm-bindgen/api/web_sys/struct.Window.html#method.fetch_with_str) 13* [`Window::fetch_with_request`](https://rustwasm.github.io/wasm-bindgen/api/web_sys/struct.Window.html#method.fetch_with_request) 14* [`Window::fetch_with_str_and_init`](https://rustwasm.github.io/wasm-bindgen/api/web_sys/struct.Window.html#method.fetch_with_str_and_init) 15* [`Window::fetch_with_request_and_init`](https://rustwasm.github.io/wasm-bindgen/api/web_sys/struct.Window.html#method.fetch_with_request_and_init) 16 17Note that different overloads can use different interfaces, and therefore can 18require different sets of cargo features to be enabled. 19 20[mdn-fetch]: https://developer.mozilla.org/en-US/docs/Web/API/WindowOrWorkerGlobalScope/fetch 21