Ninshin JavaScript Promise Obhaji

Promise duanxi biaoshi xian su zhi cao zuo de wande huan shi shibai ji qi jie guo.

Yi ge Promise ke yi you you xian zhi 3 zhong zhuang tai:

pending Chu shi zhuang tai
rejected Cao zuo shibai
fulfilled Cao zuo wande

Shi lian

// Chuang jian yi ge Promise duanxi
let myPromise = new Promise(function(myResolve, myReject) {
  let result = true;
// Zhe li fang zhi keneng chao shi zui chang de ma
  if (result == true) {
    myResolve("OK");
  }
    myReject("Error");
  }
});
// Shiyong then() xian shi jie guo
myPromise.then(x => myDisplay(x), x => myDisplay(x));

Zi jin shi yi

JavaScript Promise Fangfa he Shuxing

Mingcheng Miaoshu
Promise.all()

Cong yi zu zhi Promise fanhui yi ge dan yi de Promise.

Dang suan ge Promise dou wande shi.
Promise.allSettled()

Cong yi zu zhi Promise fanhui yi ge dan yi de Promise.

Dang suan ge Promise dou yi wande shi.
Promise.any()

Cong yi zu zhi Promise fanhui yi ge dan yi de Promise.

Dang ren yi Promise wande shi.
Promise.race()

Cong yi zu zhi Promise fanhui yi ge dan yi de Promise.

Dang jiao kuai de Promise jiejue shi.
Promise.reject() Fanhui bei juefei bing dai you zhi de Promise duanxi.
Promise.resolve() Fanhui bei jiejue bing dai you zhi de Promise duanxi.
catch() Tui gao yi ge hanchu, rang Promise bei juefei shi qing yong li.
finally() Tui gao yi ge hanchu, rang Promise wande huan zhe bei juefei shi qing yong li.
then() Tui gao liang ge hanchu, rang Promise wande huan zhe bei juefei shi qing yong li.

Ling qing cankao:

Jiaocheng:JavaScript Promise