We're looking for a user researcher to understand the needs of developers and designers. Is this you or someone you know? Check out the post: https://mzl.la/2IGzdXS

Method catch() mengembalikan Promise dan hanya setuju jika kasusnya gagal. Sama halnya dengan memenggil method Promise.prototype.then(undefined, onRejected).

Sintaks

p.catch(onRejected);

p.catch(function(reason) {
   // rejection
});

Parameter

onRejected
 Function dipanggil ketika Promise ditolak. Fungsi ini memiliki satu argumen, alasan penolakan.

Deskripsi

Method catch sangat berguna untuk menangani error di gabungan promis anda.

Contoh

Penggunaan method catch

var p1 = new Promise(function(resolve, reject) {
  resolve('Success');
});

p1.then(function(value) {
  console.log(value); // "Success!"
  throw 'oh, no!';
}).catch(function(e) {
  console.log(e); // "oh, no!"
}).then(function(){
  console.log('after a catch the chain is restored');
}, function () {
  console.log('Not fired due to the catch');
});

// The following behaves the same as above
p1.then(function(value) {
  console.log(value); // "Success!"
  return Promise.reject('oh, no!');
}).catch(function(e) {
  console.log(e); // "oh, no!"
}).then(function(){
  console.log('after a catch the chain is restored');
}, function () {
  console.log('Not fired due to the catch');
});

Promis tidak dapat mendeteksi error pada asynchronous callback

var p1 = new Promise(function(resolve, reject) {
  throw 'Uh-oh!';
});

p1.catch(function(e) {
  console.log(e); // "Uh-oh!"
});


var p2 = new Promise(function(resolve, reject) {
  setTimeout(function() {
    throw 'Uncaught Exception!';
  }, 1000);
});

p2.catch(function(e) {
  console.log(e); // This is never called
});

Spesifikasi

Spesifikasi Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
The definition of 'Promise.prototype.catch' in that specification.
Standard Initial definition in an ECMA standard.
ECMAScript Latest Draft (ECMA-262)
The definition of 'Promise.prototype.catch' in that specification.
Draft  

Kompabilitas Browser

 

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support32 Yes29 No198
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support4.4.432 Yes29 Yes8 Yes

 

Lihat Juga

Tag Dokumen dan Kontributor

Kontributor untuk laman ini: fscholz, bekti
Terakhir diperbarui oleh: fscholz,