| 2asyncPromiseawaitPromiseasyncthen async function getTitle ( url ) { let response = await fetch(url); let html = await response.text(); return html.match( /title([\s\S]+)\/title/i )[ 1 ];}getTitle( https://tc39.github.io/ecma262/ ).then( console .log) // ECMAScript 2017 Language Specification 3awaitPromiseresolvePromise async function f () { return await 123 ;}f().then(v = console .log(v)) // 123 await123Promiseresolve awaitPromiserejectrejectcatch async function f () { await Promise .reject( );}f().then(v = console .log(v)).catch(e = console .log(e)) // awaitreturnrejectcatchawaitreturn awaitPromiserejectasync async function f () { await Promise .reject( ); await Promise .resolve( hello world ); // } awaitawaitreject awaittry...catchawait async function f () { try { await Promise .reject( ); } catch (e) { } return await Promise .resolve( hello world );}f().then(v = console .log(v)) // hello world awaitPromisecatch async function f () { await Promise .reject( ).catch(e = console .log(e)); return await Promise .resolve( hello world );}f().then(v = console .log(v)) // // hello world (责任编辑：admin) |