mirror of
https://github.com/alrayyes/wiki.git
synced 2024-12-01 15:26:23 +00:00
27 lines
511 B
Markdown
27 lines
511 B
Markdown
|
---
|
||
|
|
id: 653df156-531e-48c9-a637-a1609069ff8e
|
||
|
|
title: Optional Chaining Operator (?.)
|
||
|
|
---
|
||
|
|
|
||
|
|
# Description
|
||
|
|
|
||
|
|
Permits reading the value of a property located within a chain of
|
||
|
|
connected objects without having to expressly validate that each
|
||
|
|
reference in the chain is valid.
|
||
|
|
|
||
|
|
# Syntax
|
||
|
|
|
||
|
|
``` javascript
|
||
|
|
const adventurer = {
|
||
|
|
name: "Alice",
|
||
|
|
cat: {
|
||
|
|
name: "Dinah",
|
||
|
|
},
|
||
|
|
};
|
||
|
|
|
||
|
|
const dogName = adventurer.dog?.name;
|
||
|
|
console.log(dogName); // undefined
|
||
|
|
|
||
|
|
console.log(adventurer.someNonExistentMethod?.()); // undefined
|
||
|
|
```
|