String
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 | JavaScript string value |
Copies the string's contents back and forth between the JavaScript
garbage-collected heap and the Wasm linear memory with TextDecoder
and
TextEncoder
Note: Be sure to check out the documentation for
str
to learn about some caveats when working with strings between JS and Rust.
Example Rust Usage
# #![allow(unused_variables)] #fn main() { use wasm_bindgen::prelude::*; #[wasm_bindgen] pub fn take_string_by_value(x: String) {} #[wasm_bindgen] pub fn return_string() -> String { "hello".into() } #[wasm_bindgen] pub fn take_option_string(x: Option<String>) {} #[wasm_bindgen] pub fn return_option_string() -> Option<String> { None } #}
Example JavaScript Usage
import {
take_string_by_value,
return_string,
take_option_string,
return_option_string,
} from './guide_supported_types_examples';
take_string_by_value('hello');
let s = return_string();
console.log(typeof s); // "string"
take_option_string(null);
take_option_string(undefined);
take_option_string('hello');
let t = return_option_string();
if (t == null) {
// ...
} else {
console.log(typeof s); // "string"
}