async 完全理解 - 全ての async は Promise に通ず / Guide to async, await

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4. Promise Deferred Objects async await Promise async await

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6. Promise<T> ( ) ( ) resolve(T) Promise reject(any) Promise then(f,

   f) , ,

7. Promise<T> ( ) ( ) resolve(T) Promise reject(any) Promise then(f,

   f) , ,

8. async return throw await const value = await ; console.debug(value);

   .then((value) => { console.debug(value); });
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12. const promise = new Promise(); // ... ... promise.resolve( );

    /* */ promise.reject( ); new Promise((resolve, reject) => { // ... ... resolve( ); /* */ reject( ); });

13. // Promise let resolve, reject; new Promise((_resolve, _reject) => {

    // resolve, reject resolve = _resolve; reject = _reject; }); resolve( ); /* */ reject( ); // ↑ ...

14. function () { // Promise ... const promise = new

    Promise(); // ... ( promise.resolve ) ... return promise; } const promise = (); promise.resolve(null); // resolve

15. function () { // Promise return new Promise((resolve, reject) =>

    { // ... ( resolve ) ... }); } const promise = (); // ↑ resolve

16. function (props) { // const hoge = props.something.foobar(); // Promise

    ... const promise = new Promise(); // ... ( promise.resolve ) ... return promise; } resolve( ) reject( )
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18. function () { /* ※1 */ return new Promise((resolve, reject)

    => { // reject( ) }); } const promise = (); // ↑ Promise reject ※1

19. promise.then .then((result) => { return (); // Promise }).then((result) =>

    { // result === });

20. Promise.all(Promise<T>[]): Promise<T[]> Promise.race(Promise<T>[]): Promise<T> promise.catch(f)

21. function myFunction() { A().then((resultA) => { if (resultA === "hoge")

    { B().then((resultB) => { if (resultB === "huga") C(); }); } else { D().then((resultC) => { if (resultC === "piyo") E(); }); } }); }
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24. async return throw await const value = await ; console.debug(value);

    .then((value) => { console.debug(value); });

25. await // async function myFunction() { if (await A() ===

    "hoge") { if (await B() === "huga") C(); } else { if (await D() === "piyo") E(); } } await then
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27. Promise Promise.all Promise.race await Promise.all( 1(), 2(), ...) Promise

28. async await async Promise Promise await await

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31. async await function hoge() { const async = 1; const

    await = 2; console.log(async, await); // it works } async await async function() { ... } async

32. await async function myFunction() { await 1(); // 1().then(...) 1();

    2(); // await 2(); await 3(); // 3().then(...) } 2 no-floating-promises

33. await Promise.resolve(Promise.resolve(123)); // Promise.resolve(123) 123 // Promise.resolve Promise

34. fulfill reject resolve Promise.reject(e) Promise.resolve(value) fulfill resolve reject

35. new Promise Promise. Promise

36. Promise Promise Promise = undefined; // Promise.resolve(1234); // await (async()

    => 123)(); // async await Promise Promise ZoneAwarePromise Promise Zone async await Promise.

37. await then await 14.6.13 Runtime Semantics: Evaluation 25.5.5.3 AsyncFunctionAwait (

    value ) 25.4.5.3.1 PerformPromiseThen

38. await