JavaScript: Difference between revisions

No edit summary
Line 90: Line 90:
   }
   }
}
}
</syntaxhighlight>
==Promises==
See [https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise Promises]<br>
In general, a function returns a promise if it needs to perform asyncronous tasks.<br>
<syntaxhighlight lang="javascript">
function myFunc() {
  // Do syncronous things here
  return new Promise((resolve, reject) => {
    // Do asyncronous things here
    // Return data
    resolve(myData);
    // Or if we have an error
    reject(myError);
  });
}
myFunc()
  .then(data => {
    console.log(data);
  }).catch(err => {
    console.error(err);
  });
</syntaxhighlight>
</syntaxhighlight>