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Programming cheat sheets (overapi.com)
324 points by donnemartin on May 3, 2016 | hide | past | web | favorite | 46 comments

I also like https://learnxinyminutes.com for when I need to understand some code in an unfamiliar language. That site also accepts contributions from anyone via pull request on GitHub.

Learn X in Y Minutes is also my go to site for dealing with code in an unfamiliar language. It's managed to get me through learning Ruby and Coffeescript on the job, as well as learning PHP for university.

It's a pity that nobody has done one for SQL yet, I would've thought it would be in high demand.

It's good to quickly grasp basic syntax so you can read code in unfamiliar language. However, I don't think that it's a good resource to properly learn language.

You will often miss learning the philosophy of the language (the $language_name way of doing it), the different way of thinking about the problems that the language provides and similar details, which are often not necessary to read a snippet of code, but you want to understand it in order to properly learn the language and make the most of it.

SQL is a good example of it. It might be trivial to explain the syntax of most common SQL queries, but thinking in relations and tables is not natural to most people so there's not much you can do with basic syntax.

Also helped me a lot when I was learning Javascript from Codecademy. It introduced me to Eloquent Javascript book and Mozilla Developers Network.

Impressive until you get to C++ and it turns into a random hodgepodge of 404s or really weak references (no pun intended).

Also, this same cheat sheet has been shared on HN 14 times now. Not a bad thing but interesting none the less.

>>Also, this same cheat sheet has been shared on HN 14 times now. Not a bad thing but interesting none the less.

It still gets to the front page most of the time.

If you like this sort of thing (and have a Mac), you'll probably enjoy Dash. It's particularly great to load up on anything you feel you might need before heading towards flaky international internet access for a while.


DevDocs is a great alternative for those of us that don't use Macs. Works fully in the browser, even with no network, which is kinda cool.


https://zealdocs.org/ was the one I tried, but the main problem is that it didn't support zip/tar files and Windows (explorer.exe mainly) gets very slow when there are >10 000 files in one path.

Wow it got really lots of new stuff since I last checked! The offline option sounds cool if you're working on a laptop while commuting etc.

second this. devdocs is awesome.

DevDocs is great, highly recommended!

Seems to contain javascript file from linezing which seems to be superslow and upon further examination contain malicious code(?) https://www.virustotal.com/en/domain/js.tongji.linezing.com/...

Yeah, they have a bunch of other people's content in GitHub too it appears...

I recall rosetta stones for various UNIX operating systems. There were many versions of this most of them outdated now. Quick example:


There's also Rosetta Code, very useful for finding implementations of various things in different languages.


+1 Someone had recommended this on a previous thread; and i believe this to be so cool!

Pretty neat, but the first thing I looked for was how to open a file in Python and it wasn't there. I'm guessing it's because the "File" column only displays methods on the file object, and open is a built-in function. I can see how this might be useful when context-switching between different programming languages.

Also the "Array" section refers to array.array objetcs, but, as there's no sepparate section for "Lists", they can be confused. Worst thing about this is that .byteswap would seem to be a list method (I know it isn't, but someone who's just beggining may be confused as to way the list doesn't have a bytewap() method!)

The regexp cheat sheet is missing the most important part, which is the characters you need to escape.

The R cheat sheet also looks incomplete. Is this a work in progress?

Well that's just dandy. They are plagiarising.


All those PDFs that they have taken without permission and stored in their GitHub repository are the giveaway:


When would someone actually use a cheat sheet instead of google?

Back in the day when I actually had a desk and walls on which to pin things, I printed out and stuck cheat sheets from the 4 languages in effective use in my context: SAS, R, python and C.

The lag/effort was/is far less than google if the info is right there, and I personally found I kept having brain farts where I'd temporarily forget what language the thought I was having was actually in, and could quickly touch base again by referencing the cheat sheet without bringing up the (often distracting) web browser...

You'd go to DDG and type in "git cheatsheet".

Or for the ultimate in self-referencing cheat sheets, use:


This links to:


I think this leveraging off DDG's goodies, part of their Instant Answers:


Usually when you think you can find some new treasures in there fast. I use an API cheat sheet all the time.

Also when the topic at hand isn't very google-able and the cheat sheet is the next most efficient choice.

But a lot of the time cheat sheets get useless fast.

Working in a fully offline environment, I have git repository with only documentation for everything I may need. In this situation, a cheat sheet or a searchable doc can save my day.

I think both are useful depending on the situation. Maybe a better question is why I'd want a potentially outdated list of cheat sheets instead google. I bookmarked it anyway.

To find something specific you need? probably not. Google's probably still the easiest.

To go "I want to refresh myself on X's commands and syntax", read over a short cheat sheet? Maybe

When one is exploring domain specific command sets.

This is good cheat sheets, but can we have PDF downloads for it ? Also PhalconPHP would be a great addition :)

This is pretty sweet. It's like a super lite IDE but on paper.

For C#, in the online section, you should put a link to http://www.dotnetperls.com/. It also has sections for other languages.

not a language, but this is a great redis cheat sheet https://www.cheatography.com/tasjaevan/cheat-sheets/redis/

The Java page is basically a list of links to tutorialspoint.com, which seems like an odd choice.

Would be sweet if you could customize the options in your printed sheets. Example: I know how to preform basic git operations, but sometimes I need a reminder of how to push a local branch to a remote with a different branch name.

Isn't this DuckDuckGo's cheat sheets?


I updated the git one the other day...

overapi.com can be useful if you want to discover something... but for daily use I prefer devdocs.io

A mercurial cheat-sheet would be an excellent addition to this.

I really love these cheatsheets for PHP:


A lot of the sheets are incomplete. The guitar sheet could use a basic chords sheet, that would be handy when you need to take a break from the computer.

Would be nice to see Julia, Racket, or even a Scheme.

Should fix the CSS so it looks good when printed.

nice web, but there is a bug, when u go to http://overapi.com/eclipse/ doesn't work, but it works when you go to http://overapi.com/eclipse

looks like this bug effects anything listed under the "Related" sections on any language. They all go to the "Sorry Something Wrong..." page.

Scala's says

“Every value is an object & every operation is a message send.”

I've never heard that coming from Scala.

Not as good as google

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