Tutorial by Examples: st

Fixnum#to_s takes an optional base argument and represents the given number in that base: 2.to_s(2) # => "10" 3.to_s(2) # => "11" 3.to_s(3) # => "10" 10.to_s(16) # => "a" If no argument is provided, then it represents the number in bas...

The Arbitrary class is for types that can be randomly generated by QuickCheck. The minimal implementation of Arbitrary is the arbitrary method, which runs in the Gen monad to produce a random value. Here is an instance of Arbitrary for the following datatype of non-empty lists. import Test.QuickC...

Assuming you created the serial port object s as in this example, then to close it fclose(s) However, sometimes you can accidentally lose the port (e.g. clear, overwrite, change scope, etc...), and fclose(s) will no longer work. The solution is easy fclose(instrfindall) More info at instrfin...

Parentheses are used to enclose the arguments of function calls. Using them for procedure calls can cause unexpected problems. Because they can introduce bugs, both at run-time by passing a possibly unintended value to the procedure, and at compile-time by simply being invalid syntax. Run-time Re...

It's possible to attach an object to an existing object as if there was a new property. This is called association and allows one to extend existing objects. It can be used to provide storage when adding a property via a class extension or otherwise add additional information to an existing object. ...

NSArray *array1 = [NSArray arrayWithObjects:@"one", @"two", @"three", nil]; NSArray *array2 = @[@"one", @"two", @"three"];

To search if a String contains a substring, do the following: NSString *myString = @"This is for checking substrings"; NSString *subString = @"checking"; BOOL doesContainSubstring = [myString containsString:subString]; // YES If targeting iOS 7 or OS X 10.9 (or earlier)...

Unlike classes, structures cannot inherit: class MyView: NSView { } // works struct MyInt: Int { } // error: inheritance from non-protocol type 'Int' Structures, however, can adopt protocols: struct Vector: Hashable { ... } // works

A lot of the power of ReactJS is its ability to allow nesting of components. Take the following two components: var React = require('react'); var createReactClass = require('create-react-class'); var CommentList = reactCreateClass({ render: function() { return ( <div className...

docker restart <container> [<container>...] Option --time : Seconds to wait for stop before killing the container (default 10) docker restart <container> --time 10

public class Singleton { private readonly static Singleton instance = new Singleton(); private Singleton() { } public static Singleton Instance => instance; } This implementation is thread-safe because in this case instance object is initialized in the static constructor. The ...

git shortlog summarizes git log and groups by author If no parameters are given, a list of all commits made per committer will be shown in chronological order. $ git shortlog Committer 1 (<number_of_commits>): Commit Message 1 Commit Message 2 ... Committer 2 (<number_of_...

PHP will generally correctly guess the data type you intend to use from the context it's used in, however sometimes it is useful to manually force a type. This can be accomplished by prefixing the declaration with the name of the required type in parenthesis: $bool = true; var_dump($bool); // bool...

In Python 2, exec is a statement, with special syntax: exec code [in globals[, locals]]. In Python 3 exec is now a function: exec(code, [, globals[, locals]]), and the Python 2 syntax will raise a SyntaxError. As print was changed from statement into a function, a __future__ import was also added. ...

int getListOfFriends(size_t size, int friend_indexes[]) { size_t i = 0; for (; i < size; i++) { friend_indexes[i] = i; } } C99C11 /* Type "void" and VLAs ("int friend_indexes[static size]") require C99 at least. In C11 VLAs are optional. */ void getLis...

Leiningen Note: If you're going to use Leiningen, you first need to download and install JDK 6 or newer. The easiest way to get started with Clojure is to download and install Leiningen, the de facto standard tool to manage Clojure projects. Linux: curl https://raw.githubusercontent.com/technoma...

One of the things that can really boost your productivity while writing the code is effectively navigating the workspace. This also means making it comfortable for the moment. It's possible to achieve this by adjusting which areas of workspaces you see. The buttons on the top of the navigation and ...

/** * Enables output buffer streaming. Calling this function * immediately flushes the buffer to the client, and any * subsequent output will be sent directly to the client. */ function _stream() { ob_implicit_flush(true); ob_end_flush(); }

dnf install erlang elixir

<?php for ($i = 0; $i < 10; $i++): do_something($i); endfor; ?> <?php for ($i = 0; $i < 10; $i++): ?> <p>Do something in HTML with <?php echo $i; ?></p> <?php endfor; ?>