Tutorial by Examples: ar

ArrayList is one of the inbuilt data structures in Java. It is a dynamic array (where the size of the data structure not needed to be declared first) for storing elements (Objects). It extends AbstractList class and implements List interface. An ArrayList can contain duplicate elements where it mai...

To get more information about any git command – i.e. details about what the command does, available options and other documentation – use the --help option or the help command. For example, to get all available information about the git diff command, use: git diff --help git help diff Similarl...

If you want to change the order of a character strings you can use parentheses in the pattern to group parts of the string together. These groups can in the replacement argument be addresed using consecutive numbers. The following example shows how you can reorder a vector of names of the form &quo...

This method accepts a string as input, attempts to parse it into a DateTime, and returns a Boolean result indicating success or failure. If the call succeeds, the variable passed as the out parameter is populated with the parsed result. If the parse fails, the variable passed as the out parameter i...

This method behaves as a combination of TryParse and ParseExact: It allows custom format(s) to be specified, and returns a Boolean result indicating success or failure rather than throwing an exception if the parse fails. TryParseExact(string, string, IFormatProvider, DateTimeStyles, out DateTime) ...

To see all the facts involving the le relation from the prelude: Coq < Search le. le_n: forall n : nat, n <= n le_S: forall n m : nat, n <= m -> n <= S m ... max_l: forall n m : nat, m <= n -> Nat.max n m = n max_r: forall n m : nat, n <= m -> Nat.max n m = m ... ...

Search for all facts involving a pattern in an hypothesis or conclusion: Coq < Search (_ + O). plus_n_O: forall n : nat, n = n + 0 The _ character serves as a wildcard, it can be used multiple times: Coq < Search (S _ <= _). le_S_n: forall n m : nat, S n <= S m -> n <= m le...

Let's say your launch activity is called MainActivity, in your app com.example.myapp. In the manifest: <activity android:name=".MainActivity" > <intent-filter> <action android:name="android.intent.action.MAIN"/> ...

The dimension attribute on an object specifies that that object is an array. There are, in Fortran 2008, five array natures:1 explicit shape assumed shape assumed size deferred shape implied shape Take the three rank-1 arrays2 integer a, b, c dimension(5) a ! Explicit shape (default ...

A Range cannot be created or populated the same way a string would: Sub RangeTest() Dim s As String Dim r As Range 'Specific Type of Object, with members like Address, WrapText, AutoFill, etc. ' This is how we fill a String: s = "Hello World!" ' But we can...

# example data DT = data.table(iris) DT[, Bin := cut(Sepal.Length, c(4,6,8))] summary is handy for browsing summary statistics. Besides direct usage like summary(DT), it can also be applied per-group conveniently with split: lapply(split(DT, by=c("Species", "Bin"), drop=TRU...

# example data DT = data.table(iris) DT[, Bin := cut(Sepal.Length, c(4,6,8))] To apply the same summarizing function to every column by group, we can use lapply and .SD DT[, lapply(.SD, median), by=.(Species, Bin)] # Species Bin Sepal.Length Sepal.Width Petal.Length Petal.Width # 1...

To declare a bean, simply annotate a method with the @Bean annotation or annotate a class with the @Component annotation (annotations @Service, @Repository, @Controller could be used as well). When JavaConfig encounters such a method, it will execute that method and register the return value as a b...

Command line arguments parsing is Go is very similar to other languages. In you code you just access slice of arguments where first argument will be the name of program itself. Quick example: package main import ( "fmt" "os" ) func main() { progName := o...

Throughout the topics and examples here we'll see many declarations of variables, functions and so on. As well as their name, data objects may have attributes. Covered in this topic are declaration statements like integer, parameter :: single_kind = kind(1.) which gives the object single_kind...

If your team is following a rebase-based workflow, it may be a advantageous to setup git so that each newly created branch will perform a rebase operation, instead of a merge operation, during a git pull. To setup every new branch to automatically rebase, add the following to your .gitconfig or .gi...

To change the URL of the repository you want your remote to point to, you can use the set-url option, like so: git remote set-url <remote_name> <remote_repository_url> Example: git remote set-url heroku https://git.heroku.com/fictional-remote-repository.git

Middleware are attached to the app object, usually before listen is called. Example of a simple logging middleware: app.use(function (req, res, next) { console.log(`${req.method}: ${req.url}`) next() }) All this will do is log GET: /example if you where to GET localhost:3000/example. ...

If we would like to limit the access to our app, we could write a middleware for that too! This example only grants you access on thrusdays, but a real world example could, for example, be user authentication. A good place to put this would be after the logging middleware but before any content is s...

Command line arguments given for the script. The options for Ruby interpreter are already removed.