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"then", "catch" and "finally" methods

Unlocking promise methods in JavaScript

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Consider the following JavaScript code snippet. The 'then', 'catch', and 'finally' keywords are used for promise chaining. What are their exact roles in the chaining process and what order will they be executed in?


let dataFetch = new Promise((resolve, reject) => {
  setTimeout(() => {
    if(Math.random() > 0.5) {
      resolve('Data fetched successfully!');
    } else {
      reject('Data fetching failed!');
    }
  }, 2000);
});

dataFetch
  .then(response => {
    console.log(response);
    return 'Processing data...';
  })
  .then(message => console.log(message))
  .catch(error => console.error(error))
  .finally(() => console.log('Operation Complete'));

Select one option from the list

'catch' handles an unsuccessful outcome and errors in 'then'; 'finally' will be executed immediately after 'catch', whether or not an error has been thrown.

All 'then' and 'catch' methods are executed first in the order they appear in the chain; 'finally' is only called if no errors have been thrown in any preceding 'then' methods.

'finally' executes operations that occur regardless of the outcome first; 'then' and 'catch' handle successful outcomes and errors respectively.

'then' handles a successful outcome and operations within 'then' are executed sequentially; 'catch' handles an unsuccessful outcome; 'finally' will be executed at the end regardless of the outcome.

'then' displays the fetch response, 'then' logs 'Processing data...', 'catch' deals with errors, and 'finally' logs 'Operation Complete'; these methods will run in this order regardless of the outcome.

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