This is the unpublished documentation of wasm-bindgen, the published documentation is available on the main Rust and WebAssembly documentation site . Features documented here may not be available in released versions of wasm-bindgen.

`Box<[JsValue]>`

`T` parameter	`&T` parameter	`&mut T` parameter	`T` return value	`Option<T>` parameter	`Option<T>` return value	JavaScript representation
Yes	No	No	Yes	Yes	Yes	A JavaScript `Array` object

Example Rust Usage


# #![allow(unused_variables)]
#fn main() {
use wasm_bindgen::prelude::*;

#[wasm_bindgen]
pub fn take_boxed_js_value_slice_by_value(x: Box<[JsValue]>) {}

#[wasm_bindgen]
pub fn return_boxed_js_value_slice() -> Box<[JsValue]> {
    vec![JsValue::NULL, JsValue::UNDEFINED].into_boxed_slice()
}

#[wasm_bindgen]
pub fn take_option_boxed_js_value_slice(x: Option<Box<[JsValue]>>) {}

#[wasm_bindgen]
pub fn return_option_boxed_js_value_slice() -> Option<Box<[JsValue]>> {
    None
}

#}

Example JavaScript Usage

import {
  take_boxed_js_value_slice_by_value,
  return_boxed_js_value_slice,
  take_option_boxed_js_value_slice,
  return_option_boxed_js_value_slice,
} from './guide_supported_types_examples';

take_boxed_js_value_slice_by_value([null, true, 2, {}, []]);

let values = return_boxed_js_value_slice();
console.log(values instanceof Array); // true

take_option_boxed_js_value_slice(null);
take_option_boxed_js_value_slice(undefined);
take_option_boxed_js_value_slice([1, 2, 3]);

let maybeValues = return_option_boxed_js_value_slice();
if (maybeValues == null) {
  // ...
} else {
  console.log(maybeValues instanceof Array); // true
}