1.await必須在async定義的方法中使用
let e = await 78910;
console.log(e);
- 1
- 2
2.當await右邊爲一個PromiseState爲fulfilled的Promise對象時,則返回其PromiseResult值
async function main() {
let p = new Promise((resolve, reject) => {
resolve(156);
});
let result = await p;
console.log(result);
let p1 = new Promise((resolve, reject) => {
reject(177);
});
try {
let result1 = await p1;
} catch (e) {
console.log(e);
}
}
main();
3.當await右邊爲爲一個PromiseResult爲rejected的Promise對象時,需要trycatch獲取其PromiseResult
async function main() {
let p = new Promise((resolve, reject) => {
resolve(156);
});
let result = await p;
console.log(result);
let p1 = new Promise((resolve, reject) => {
reject(177);
});
try {
let result1 = await p1;
} catch (e) {
console.log(e);
}
}
main();
4.如果await右邊爲一個非Promise對象,則直接返回右邊內容
async function main() {
let e = await 78910;
console.log(e);
}
main();