No error , No gain

I saw some code that seems to use an operator I don't recognize, in the form of two exclamation points, like so: !!. Can someone please tell me what this operator does? The context in which I saw this was, this.vertical = vertical !== undefined ? !!vertical : this.vertical; Converts Object to boolean. If it was falsey (e.g. 0, null, undefined, etc.), it will be false, otherwise, true. !oObject /..

In an HTML table, the cellpadding and cellspacing can be set like this: How can the same be accomplished using CSS? Basics For controlling "cellpadding" in CSS, you can simply use padding on table cells. E.g. for 10px of "cellpadding": td { padding: 10px; } For "cellspacing", you can apply the border-spacing CSS property to your table. E.g. for 10px of "cellspacing": table { border-spacing: 10px..

All I want is to get the website URL. Not the URL as taken from a link. On the page loading I need to be able to grab the full, current URL of the website and set it as a variable to do with as I please. Use: window.location.href As noted in the comments, the line below works, but it is bugged for Firefox. document.URL See URL of type DOMString, readonly. Community Wiki URL Info Access JavaScrip..

I am looking for a JavaScript array insert method, in the style of: arr.insert(index, item) Preferably in jQuery, but any JavaScript implementation will do at this point. You want the splice function on the native array object. arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an arr..

I am a bit puzzled by the following code: d = {'x': 1, 'y': 2, 'z': 3} for key in d: print (key, 'corresponds to', d[key]) What I don't understand is the key portion. How does Python recognize that it needs only to read the key from the dictionary? Is key a special word in Python? Or is it simply a variable? key is just a variable name. for key in d: will simply loop over the keys in the diction..

I started some work on a new feature and after coding for a bit, I decided this feature should be on its own branch. How do I move the existing uncommitted changes to a new branch and reset my current one? I want to reset my current branch while preserving existing work on the new feature. Update 2020 / Git 2.23 Git 2.23 adds the new switch subcommand in an attempt to clear some of the confusion..

Over the years I have slowly developed a regular expression that validates most email addresses correctly, assuming they don't use an IP address as the server part. I use it in several PHP programs, and it works most of the time. However, from time to time I get contacted by someone that is having trouble with a site that uses it, and I end up having to make some adjustment (most recently I real..

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 was looking at the new APIs introduced in Android 4.2. While looking at the UserManager class I came across the following method: public boolean isUserAGoat() Used to determine whether the user making..

My initial commit contained some log files. I've added *log to my .gitignore, and now I want to remove the log files from my repository. git rm mylogfile.log will remove a file from the repository, but will also remove it from the local file system. How can I remove this file from the repo without deleting my local copy of the file? From the man file: When --cached is given, the staged content h..

How can I create or use a global variable in a function? If I create a global variable in one function, how can I use that global variable in another function? Do I need to store the global variable in a local variable of the function which needs its access? You can use a global variable within other functions by declaring it as global within each function that assigns a value to it: globvar = 0..

Does anybody know how to easily undo a git rebase? The only way that comes to mind is to go at it manually: git checkout the commit parent to both of the branches then create a temp branch from there cherry-pick all commits by hand replace the branch in which I rebased by the manually-created branch In my current situation this is gonna work because I can easily spot commits from both branches (..

I just had an interview where I was asked to create a memory leak with Java. Needless to say, I felt pretty dumb having no clue on how to even start creating one. What would an example be? Here's a good way to create a true memory leak (objects inaccessible by running code but still stored in memory) in pure Java: The application creates a long-running thread (or use a thread pool to leak even f..

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 looking for a string.contains or string.indexof method in Python. I want to do: if not somestring.contains("blah"): continue You can use the in operator: if "blah" not in somestring: continue Michael Mrozek If it's just a substring search you ..

Consider the following code: 0.1 + 0.2 == 0.3 -> false 0.1 + 0.2 -> 0.30000000000000004 Why do these inaccuracies happen? Binary floating point math is like this. In most programming languages, it is based on the IEEE 754 standard. The crux of the problem is that numbers are represented in this format as a whole number times a power of two; rational numbers (such as 0.1, which is 1/10) whose den..

How do I generate a random int value in a specific range? I have tried the following, but those do not work: Attempt 1: randomNum = minimum + (int)(Math.random() * maximum); Bug: randomNum can be bigger than maximum. Attempt 2: Random rn = new Random(); int n = maximum - minimum + 1; int i = rn.nextInt() % n; randomNum = minimum + i; Bug: randomNum can be smaller than minimum. In Java 1.7 or lat..

Closed. This question needs to be more focused. It is not currently accepting answers. Closed 6 years ago. Locked. This question and its answers are locked because the question is off-topic but has historical significance. It is not currently accepting new answers or interactions. Suppose I'm familiar with developing client-side applications in jQuery, but now I'd like to start using AngularJS. ..

Within my master branch, I did a git merge some-other-branch locally, but never pushed the changes to origin master. I didn't mean to merge, so I'd like to undo it. When doing a git status after my merge, I was getting this message: # On branch master # Your branch is ahead of 'origin/master' by 4 commits. Based upon some instructions I found, I tried running git revert HEAD -m 1 but now I'm get..

I have an EditText and a Button in my layout. After writing in the edit field and clicking on the Button, I want to hide the virtual keyboard when touching outside the keyboard. I assume that this is a simple piece of code, but where can I find an example of it? You can force Android to hide the virtual keyboard using the InputMethodManager, calling hideSoftInputFromWindow, passing in the token ..

People talk about URLs, URIs, and URNs as if they're different things, but they look the same to the naked eye. What are the distinguishable differences between them? URIs identify and URLs locate; however, locators are also identifiers, so every URL is also a URI, but there are URIs which are not URLs. Examples Roger Pate This is my name, which is an identifier. It is like a URI, but cannot be ..

I'm stuck and cannot escape. It says: "type :quit to quit VIM" But when I type that it simply appears in the object body. Hit the Esc key to enter "Normal mode". Then you can type : to enter "Command-line mode". A colon (:) will appear at the bottom of the screen and you can type in one of the following commands. To execute a command, press the Enter key. :q to quit (short for :quit) :q! to quit..