Thanks to visit codestin.com
Credit goes to github.com

Skip to content

Functions are cleaner than subclasses #116

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Closed
wants to merge 8 commits into from
Closed

Functions are cleaner than subclasses #116

Changes from all commits
Commits
Show all changes
8 commits
Select commit Hold shift + click to select a range
a9894e9
Functions are often cleaner than subclasses
DavidVujic Jan 11, 2017
75c9b76
Merge remote-tracking branch 'upstream/master'
DavidVujic Jan 12, 2017
7ea0e67
diff code same as updated previous example
DavidVujic Jan 12, 2017
c3fd769
refactor: rewrite text, use Bad/Good format
DavidVujic Jan 12, 2017
5d54b58
refactor: rewrite text
DavidVujic Jan 12, 2017
ec2aee6
Merge remote-tracking branch 'upstream/master'
DavidVujic Jan 14, 2017
8e52681
updated code example after merge from master
DavidVujic Jan 14, 2017
77acb99
class extending a global object is bad
DavidVujic Jan 17, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
17 changes: 10 additions & 7 deletions README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -558,8 +558,13 @@ extend JavaScript's native Array method to have a `diff` method that could
show the difference between two arrays? You could write your new function
to the `Array.prototype`, but it could clash with another library that tried
to do the same thing. What if that other library was just using `diff` to find
the difference between the first and last elements of an array? This is why it
would be much better to just use ES2015/ES6 classes and simply extend the `Array` global.
the difference between the first and last elements of an array?

One option is to use ES2015/ES6 classes. Classes are useful when you need state.
Consider writing a simple function if state is not an issue. Also, when extending an object,
features will be limited to instances of that subclass only. Another drawback is
(especially when extending built in globals like Array) that instances must be
created using the 'new' keyword. A better option is to write a stateless function.

**Bad:**
```javascript
Expand All @@ -571,11 +576,9 @@ Array.prototype.diff = function diff(comparisonArray) {

**Good:**
```javascript
class SuperArray extends Array {
diff(comparisonArray) {
const hash = new Set(comparisonArray);
return this.filter(elem => !hash.has(elem));
}
function diff(first, second) {
const hash = new Set(second);
return first.filter(elem => !hash.has(elem));
}
```
**[⬆ back to top](#table-of-contents)**
Expand Down