Tutorial by Examples: r

Although it's bad practice, it's possible to add multiple return statements in a exception handling block: public static int returnTest(int number){ try{ if(number%2 == 0) throw new Exception("Exception thrown"); else return x; } catch(Exception e){ ...

LISP and Scheme's greatest advantage over other mainstream programming language is their macro system. Unlike the C preprocessor and other macro languages, Scheme macros take parsed code as input and return expanded code as output. This is one of the applications of Scheme's “code is data” phrase, a...

In this example we want to create a class that will generate and output to console, a random number between a range of two integers which are passed as arguments during the initialization. public class SimpleRangeRandom implements Runnable { private int min; private int max; pr...

When you implement java.io.Serializable interface to make a class serializable, the compiler looks for a static final field named serialVersionUID of type long. If the class doesn't have this field declared explicitly then the compiler will create one such field and assign it with a value which come...

Converting an integer type to the corresponding promoted type is better than converting it to some other integer type. void f(int x); void f(short x); signed char c = 42; f(c); // calls f(int); promotion to int is better than conversion to short short s = 42; f(s); // calls f(short); exact mat...

To publish public repositories with a free npm account, you initially need to publish the module with access of public. One way to do this is to set the config for npm to read in packages.json as follows: "publishConfig": { "access": "public" }, you can also use...

Download the Atlassian conversion utility here. This utility requires Java, so please ensure that you have the Java Runtime Environment JRE installed on the machine you plan to do the conversion. Use the command java -jar svn-migration-scripts.jar verify to check if your machine is missing any of t...

The macro WITH-INPUT-FROM-STRING can be used to make a stream from a string. (with-input-from-string (str "Foobar") (loop for i from 0 for char = (read-char str nil nil) while char do (format t "~d: ~a~%" i char))) ; 0: F ; 1: o ; 2: o ; 3: b ;...

The macro WITH-OUTPUT-TO-STRING can be used to create a string output stream, and return the resulting string at the end. (with-output-to-string (str) (write-line "Foobar!" str) (write-string "Barfoo!" str)) ;=> "Foobar! ; Barfoo!" The same can be done ...

Gray streams are a non-standard extension that allows user defined streams. It provides classes and methods that the user can extend. You should check your implementations manual to see if it provides Gray streams. For a simple example, a character input stream that returns random characters could ...

A file can be opened for reading as a stream using WITH-OPEN-FILE macro. (with-open-file (file #P"test.file") (loop for i from 0 for line = (read-line file nil nil) while line do (format t "~d: ~a~%" i line))) ; 0: Foobar ; 1: Barfoo ; 2: Quuxbar...

A file can be opened for writing as a stream using WITH-OPEN-FILE macro. (with-open-file (file #P"test.file" :direction :output :if-exists :append :if-does-not-exist :create) (dolist (line '("Foobar" &q...

Swift webview.reload() Objective-C [webview reload];

git show shows various Git objects. For commits: Shows the commit message and a diff of the changes introduced. CommandDescriptiongit showshows the previous commitgit show @~3shows the 3rd-from-last commit For trees and blobs: Shows the tree or blob. CommandDescriptiongit show @~3:shows the ...

Whatever you do to customize Vim, it should NEVER happen outside of $HOME: on Linux, BSD and Cygwin, $HOME is usually /home/username/, on Mac OS X, $HOME is /Users/username/, on Windows, $HOME is usually C:\Users\username\. The canonical location for your vimrc and your vim directory is at ...

Like most scripting languages, vimscript has variables. One can define a variable with the :let command: let variable = value and delete it with :unlet: unlet variable In Vim, variables can be scoped by prepending a single letter and a colon to their name. Plugin authors use that feature to...

Autocommand groups are good for organization but they can be useful for debugging too. Think of them as small namespaces that you can enable/disable at will. Example augroup MyGroup " Clear the autocmds of the current group to prevent them from piling " up each time you rel...

Some formats can take additional parameters, such as the width of the formatted string, or the alignment: >>> '{:.>10}'.format('foo') '.......foo' Those can also be provided as parameters to format by nesting more {} inside the {}: >>> '{:.>{}}'.format('foo', 10) '.......

By default the built-in Request Localization middleware only supports setting culture via query, cookie or Accept-Language header. This example shows how create a middleware which allows to set the culture as part of the path like in /api/en-US/products. This example middleware assumes the locale t...

Avoid Ambiguity The name of classes, structures, functions and variables should avoid ambiguity. Example: extension List { public mutating func remove(at position: Index) -> Element { // implementation } } The function call to this function will then look like this: li...