JavaScript Optional Chaining

# JavaScript Optional Chaining

The optional chaining (?.) operator accesses an object's property or calls a function. If the object accessed or function called is undefined or null, it returns undefined instead of throwing an error.

#### First Seen
```javascript
if (HTMLScriptElement.supports?.("importmap")) {
  console.log("Browser supports import maps.");
}
```
from [Mozilla JavaScript Modules](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Guide/Modules)

#### JavaScript Demo: Expressions - Optional chaining operator
```javascript
const adventurer = {
  name: 'Alice',
  cat: {
    name: 'Dinah'
  }
};

const dogName = adventurer.dog?.name;
console.log(dogName);
// expected output: undefined

console.log(adventurer.someNonExistentMethod?.());
// expected output: undefined
```

#### Syntax
```javascript
obj.val?.prop
obj.val?.[expr]
obj.func?.(args)
```

#### Source

**Reference:** [Mozilla JavaScript Optional chaining operator](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Optional_chaining)

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