No error , No gain

Yesterday I was pairing the socks from the clean laundry and figured out the way I was doing it is not very efficient. I was doing a naive search — picking one sock and "iterating" the pile in order to find its pair. This requires iterating over n/2 * n/4 = n2/8 socks on average. As a computer scientist I was thinking what I could do? Sorting (according to size/color/...) of course came to mind ..

How can I squash my last X commits together into one commit using Git? You can do this fairly easily without git rebase or git merge --squash. In this example, we'll squash the last 3 commits. If you want to write the new commit message from scratch, this suffices: git reset --soft HEAD~3 && git commit If you want to start editing the new commit message with a concatenation of the existing commi..

After an AJAX request, sometimes my application may return an empty object, like: var a = {}; How can I check whether that's the case? ECMA 5+: // because Object.keys(new Date()).length === 0; // we have to do some additional check obj // null and undefined check && Object.keys(obj).length === 0 && obj.constructor === Object Note, though, that this creates an unnecessary array (the return value ..

In SQL Server, it is possible to insert rows into a table with an INSERT.. SELECT statement: INSERT INTO Table (col1, col2, col3) SELECT col1, col2, col3 FROM other_table WHERE sql = 'cool' Is it also possible to update a table with SELECT? I have a temporary table containing the values and would like to update another table using those values. Perhaps something like this: UPDATE Table SET col1,..

I want to be able to do the following: Create a local branch based on some other (remote or local) branch (via git branch or git checkout -b) Push the local branch to the remote repository (publish), but make it trackable so git pull and git push will work immediately. How do I do that? I know about --set-upstream in Git 1.7, but that is a post-creation action. I want to find a way to make a sim..

How can you enumerate an enum in C#? E.g. the following code does not compile: public enum Suit { Spades, Hearts, Clubs, Diamonds } public void EnumerateAllSuitsDemoMethod() { foreach (Suit suit in Suit) { DoSomething(suit); } } And it gives the following compile-time error: 'Suit' is a 'type' but is used like a 'variable' It fails on the Suit keyword, the second one. foreach (Suit suit in (Suit..

I use object != null a lot to avoid NullPointerException. What is an alternative to: if (someobject != null) { someobject.doCalc(); } This to me sounds like a reasonably common problem that junior to intermediate developers tend to face at some point: they either don't know or don't trust the contracts they are participating in and defensively overcheck for nulls. Additionally, when writing thei..

This question's answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. I wrote the wrong thing in a commit message. How can I change the message? The commit has not been pushed yet. Amending the most recent commit message git commit --amend will open your editor, allowing you to change the commit message of the most ..

Is it possible to toggle the visibility of an element, using the functions .hide(), .show() or .toggle()? How would you test if an element is visible or hidden? Since the question refers to a single element, this code might be more suitable: // Checks CSS content for display:[none|block], ignores visibility:[true|false] $(element).is(":visible"); // The same works with hidden $(element).is(":hid..

Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. I mistakenly added files to Git using the command: git add myfile.txt I have not yet run git commit. Is there a way to undo this, so these files won't be included in the commit? You can undo git add bef..

How do I discard changes in my working copy that are not in the index? For all unstaged files in current working directory use: git checkout -- . For a specific file use: git checkout -- path/to/file/to/revert -- here to remove ambiguity (this is known as argument disambiguation). For Git 2.23 onwards, one may want to use the more specific git restore . resp. git restore path/to/file/to/revert t..

Programming language books explain that value types are created on the stack, and reference types are created on the heap, without explaining what these two things are. I haven't read a clear explanation of this. I understand what a stack is. But, Where and what are they (physically in a real computer's memory)? To what extent are they controlled by the OS or language run-time? What is their sco..

This question's answers are a community effort. Edit existing answers to improve this post. It is not currently accepting new answers or interactions. I'm using JSLint to go through JavaScript, and it's returning many suggestions to replace == (two equals signs) with === (three equals signs) when doing things like comparing idSele_UNVEHtype.value.length == 0 inside of an if statement. Is there a..

Is there something in JavaScript similar to @import in CSS that allows you to include a JavaScript file inside another JavaScript file? The old versions of JavaScript had no import, include, or require, so many different approaches to this problem have been developed. But since 2015 (ES6), JavaScript has had the ES6 modules standard to import modules in Node.js, which is also supported by most m..

According to RFC 2616, § 9.5, POST is used to create a resource: The POST method is used to request that the origin server accept the entity enclosed in the request as a new subordinate of the resource identified by the Request-URI in the Request-Line. According to RFC 2616, § 9.6, PUT is used to create or replace a resource: The PUT method requests that the enclosed entity be stored under the s..

I accidentally committed the wrong files to Git, but didn't push the commit to the server yet. How can I undo those commits from the local repository? The only way seems to be to copy the edits in some kind of GUI text editor, then wipe the whole local clone, then re-clone the repository, then re-applying the edits. However, This can cause data loss. It's very hard to do this when only an accide..

I want to delete a branch both locally and remotely. Failed Attempts to Delete a Remote Branch $ git branch -d remotes/origin/bugfix error: branch 'remotes/origin/bugfix' not found. $ git branch -d origin/bugfix error: branch 'origin/bugfix' not found. $ git branch -rd origin/bugfix Deleted remote branch origin/bugfix (was 2a14ef7). $ git push Everything up-to-date $ git pull From github.com:git..

Want to improve this post? Provide detailed answers to this question, including citations and an explanation of why your answer is correct. Answers without enough detail may be edited or deleted. I'm trying to find a way to scan my entire Linux system for all files containing a specific string of text. Just to clarify, I'm looking for text within the file, not in the file name. When I was lookin..

If I run the following program, which parses two date strings referencing times 1 second apart and compares them: public static void main(String[] args) throws ParseException { SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); String str3 = "1927-12-31 23:54:07"; String str4 = "1927-12-31 23:54:08"; Date sDt3 = sf.parse(str3); Date sDt4 = sf.parse(str4); long ld3 = sDt3.getTime(..

How do you delete untracked local files from your current working tree? git-clean - Remove untracked files from the working tree Synopsis git clean [-d] [-f] [-i] [-n] [-q] [-e ] [-x | -X] [--] …​ Description Cleans the working tree by recursively removing files that are not under version control, starting from the current directory. Normally, only files unknown to Git are removed, but if the -x..