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JavaScript - Optional Chaining & Nullish Coalescing

redraushan profile image Raushan Sharma Updated on ・2 min read

Optional Chaining & Nullish Coalescing are coming to JavaScript! They're short and readable. Both these features are currently in stage 3, however we can start using the same with the help of following plugins that Babel provides:

@babel/plugin-proposal-optional-chaining
@babel/plugin-proposal-nullish-coalescing-operator

The optional chaining operator can be combined with the nullish coalescing ?? operator when a non-undefined default value is needed. This enables safe deep property access with a specified default value, addressing a common use case that previously required libraries such as lodash’s _.get:

const object = { id: 123, names: { first: 'Alice', last: 'Smith' }};

{ // With lodash:
  const firstName = _.get(object, 'names.first');
  // → 'Alice'

  const middleName = _.get(object, 'names.middle', '(no middle name)');
  // → '(no middle name)'
}

{ // With optional chaining and nullish coalescing:
  const firstName = object?.names?.first ?? '(no first name)';
  // → 'Alice'

  const middleName = object?.names?.middle ?? '(no middle name)';
  // → '(no middle name)'

}

Github:
https://github.com/tc39/proposal-nullish-coalescing
https://github.com/tc39/proposal-optional-chaining

V8.dev:
https://v8.dev/features/nullish-coalescing
https://v8.dev/features/optional-chaining

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Happy coding :)

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