How can I use optional chaining with arrays and functions?

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You need to put a . after the ? to use optional chaining:

myArray.filter(x => x.testKey === myTestKey)?.[0]

Playground link

Using just the ? alone makes the compiler think you’re trying to use the conditional operator (and then it throws an error since it doesn’t see a : later)

Optional chaining isn’t just a TypeScript thing – it is a finished proposal in plain JavaScript too.

It can be used with bracket notation like above, but it can also be used with dot notation property access:

const obj = {
  prop2: {
    nested2: 'val2'
  }
};

console.log(
  obj.prop1?.nested1,
  obj.prop2?.nested2
);

And with function calls:

const obj = {
  fn2: () => console.log('fn2 running')
};

obj.fn1?.();
obj.fn2?.();

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