Tutorial by Examples: u

Lambdas are meant to provide inline implementation code for single method interfaces and the ability to pass them around as we have been doing with normal variables. We call them Functional Interface. For example, writing a Runnable in anonymous class and starting a Thread looks like: //Old way n...

Random UUID Swift func randomUUID() -> NSString{ return NSUUID.UUID().UUIDString() } Objective-C + (NSString *)randomUUID { if(NSClassFromString(@"NSUUID")) { // only available in iOS >= 6.0 return [[NSUUID UUID] UUIDString]; } CFUUIDRef uuidRef = ...

server { server_name example.com; return 301 $scheme://example.net$request_uri; }

1.8 Run: $ git mv old/path/to/module new/path/to/module 1.8 Edit .gitmodules and change the path of the submodule appropriately, and put it in the index with git add .gitmodules. If needed, create the parent directory of the new location of the submodule (mkdir -p new/path/to). M...

Since Ionic 2 is getting better and better every day, please always check the official documentation to keep track of the latest changes and improvements. Prerequisites: You will need NodeJS in order to build Ionic 2 projects. You can download and install node here and learn more about npm and the...

One way to calculate the Big-O value of a procedure you've written is to determine which line of code runs the most times in your function, given your input size n. Once you have that number, take out all but the fastest-growing terms and get rid of the coefficents - that is the Big-O notation of yo...

You can quickly switch to the previous branch using git checkout -

Locally created images can be pushed to Docker Hub or any other docker repo host, known as a registry. Use docker login to sign in to an existing docker hub account. docker login Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https...

Run the install on a single run command to merge the update and install. If you add more packages later, this will run the update again and install all the packages needed. If the update is run separately, it will be cached and package installs may fail. Setting the frontend to noninteractive and pa...

Open Repo Create new repo (My advice first add pods on a temporary repo before adding to your original project) Fill Repository name with your repo name. I'll use "myrepo" for this tutorial and will use "<" and ">" symbols for the parts you should change to yo...

Now you have aws cli installed, you'll have to configure it access your AWS resources. You can have multiple profiles like test, dev, prod, etc profiles. So let's assume you want to configure it for your test environment. aws configure --profile=test It will ask for following information: AWS A...

In-place editing, while common, is a non-standard feature. A viable alternative would be to use an intermediate file to either store the original, or the output. sed 'sed commands' > file.out && mv file.out file # or mv file file.orig && sed 'sed commands' file.orig > file ...

Update your project with git pull origin master Update s.version inside MyRepo.podspec Check local errors with pod lib lint MyRepo.podspec git add . & git commit -m "Update pods version" git push origin master Make a new release pod trunk push MyRepo.podspec Source

Consider the Node class having 3 members data, left child pointer and right child pointer like below. public class Node { public int data; public Node left; public Node right; public Node(int data){ this.data = data; } } We can traverse the tree construct...

You will need to set your base URL in application/config/config.php If it is not set, then CodeIgniter will try to guess the protocol and path to your installation, but due to the security concerns the hostname will be set to $_SERVER['SERVER_ADDR'] if available, or localhost otherwise. The auto...

First you have to set up a new Scrapy project. Enter a directory where you’d like to store your code and run: scrapy startproject projectName To scrape we need a spider. Spiders define how a certain site will be scraped. Here’s the code for a spider that follows the links to the top voted questi...

About Akavache Akavache is an incredibly useful library providing reach functionality of caching your data. Akavache provides a key-value storage interface and works on the top of SQLite3. You do not need to keep your schema synced as it's actually No-SQL solution which makes it perfect for most of...

Imagine you are on the master branch and something is not working as expected (a regression was introduced), but you don't know where. All you know is, that is was working in the last release (which was e.g., tagged or you know the commit hash, lets take old-rel here). Git has help for you, finding...

In your Storyboard, add a UITableView object on your UIViewController and let it cover the entire view. Setup the UITableviewDataSource and UITableviewDelegate connections. Objective-C In your .h file NSMutableArray *arrayForBool; NSMutableArray *sectionTitleArray; In your .m file - (void)vi...

We can directly copy data from a source to a data sink using a loop. In this example, we are reading data from an InputStream and at the same time, writing to an OutputStream. Once we are done reading and writing, we have to close the resource. public void copy(InputStream source, OutputStream dest...