mirror of
https://github.com/alrayyes/wiki.git
synced 2024-11-22 11:36:23 +00:00
32 lines
620 B
Markdown
32 lines
620 B
Markdown
---
|
|
date: 20200826
|
|
id: 7b46ba87-7328-479c-8d79-badb24ed7b19
|
|
title: JavaScript object operators
|
|
---
|
|
|
|
# Delete operator
|
|
|
|
The `delete` operator deletes a binding (duh)
|
|
|
|
``` javascript
|
|
let anObject = {left: 1, right: 2};
|
|
console.log(anObject.left);
|
|
delete anObject.left;
|
|
console.log(anObject.left);
|
|
console.log("left" in anObject);
|
|
console.log("right" in anObject);
|
|
```
|
|
|
|
# In operator
|
|
|
|
The `in` operator tells you whether and object has a property with that
|
|
name
|
|
|
|
``` javascript
|
|
let Object = {
|
|
thisPropertyExists: true
|
|
}
|
|
|
|
console.log("thisPropertyExists" in Object)
|
|
console.log("thisPropertyDoesNotExist" in Object)
|
|
```
|