Tutorial by Examples: t

Ruby extends the standard group syntax (...) with a named group, (?<name>...). This allows for extraction by name instead of having to count how many groups you have. name_reg = /h(i|ello), my name is (?<name>.*)/i #i means case insensitive name_input = "Hi, my name is Zaphod Be...

Common mobile-optimized sites use the <meta name="viewport"> tag like this: <meta name="viewport" content="width=device-width, initial-scale=1"> The viewport element gives the browser instructions on how to control the page's dimensions and scaling based...

Assembly language is a human readable form of machine language or machine code which is the actual sequence of bits and bytes on which the processor logic operates. It is generally easier for humans to read and program in mnemonics than binary, octal or hex, so humans typically write code in assemb...

Syntax {condition-to-evaluate} ? {statement-executed-on-true} : {statement-executed-on-false} As shown in the syntax, the Conditional Operator (also known as the Ternary Operator1) uses the ? (question mark) and : (colon) characters to enable a conditional expression of two possible outcomes. It c...

To make express web application modular use router factories: Module: // greet.js const express = require('express'); module.exports = function(options = {}) { // Router factory const router = express.Router(); router.get('/greet', (req, res, next) => { res.end(options....

You can use the reversed function which returns an iterator to the reversed list: In [3]: rev = reversed(numbers) In [4]: rev Out[4]: [9, 8, 7, 6, 5, 4, 3, 2, 1] Note that the list "numbers" remains unchanged by this operation, and remains in the same order it was originally. To r...

After receiving the arguments, you can print them as follows: int main(int argc, char **argv) { for (int i = 1; i < argc; i++) { printf("Argument %d: [%s]\n", i, argv[i]); } } Notes The argv parameter can be also defined as char *argv[]. argv[0] may co...

Selenium Grid Node configuration resides on the Node itself and holds the information about network configuration and Node capabilities. The configuration can be applied in various ways: Default Configuration JSON Configuration Command line Configuration JSON Configuration The node configur...

In Python 3 and higher, print is a function rather than a keyword. print('hello world!') # out: hello world! foo = 1 bar = 'bar' baz = 3.14 print(foo) # out: 1 print(bar) # out: bar print(baz) # out: 3.14 You can also pass a number of parameters to print: print(foo, bar, b...

Create a receiver. This class will receive the intent and handle it how you wish. public class AlarmReceiver extends BroadcastReceiver { @Override public void onReceive(Context context, Intent intent) { // Handle intent int reqCode = intent.getExtras().getInt(&...

Good for quick notifications that don't require interaction. Swift let alert = UIAlertController(title: "Toast", message: "Hello World", preferredStyle: .Alert) presentViewController(alert, animated: true) { let delay_s:Double = 2 let delayTime = dispatch_time(DI...

The data.table package introduces the function fread. While it is similar to read.table, fread is usually faster and more flexible, guessing the file's delimiter automatically. # get the file path of a CSV included in R's utils package csv_path <- system.file("misc", "exDIF.csv&q...

Create a XIB file Xcode Menu Bar > File > New > File. Select iOS, User Interface and then "View": Give your XIB a name (yes, we are doing a Pokemon example 👾). Remember to check your target and hit "Create". Design your view To make things easier, set:...

There are several R packages to read excel files, each of which using different languages or resources, as summarized in the following table: R packageUsesxlsxJavaXLconnectJavaopenxlsxC++readxlC++RODBCODBCgdataPerl For the packages that use Java or ODBC it is important to know details about your s...

if let Combines a pattern match and an if statement, and allows for brief non-exhaustive matches to be performed. if let Some(x) = option { do_something(x); } This is equivalent to: match option { Some(x) => do_something(x), _ => {}, } These blocks can also have e...

The standard doesn't specify if char should be signed or unsigned. Different compilers implement it differently, or might allow to change it using a command line switch.

The following types are defined as integral types: char Signed integer types Unsigned integer types char16_t and char32_t bool wchar_t With the exception of sizeof(char) / sizeof(signed char) / sizeof(unsigned char), which is split between § 3.9.1.1 [basic.fundamental/1] and § 5.3.3.1 [ex...

Background threads cannot modify the UI; almost all UIKit methods must be called on the main thread. From a subclass of NSObject (including any UIViewController or UIView): InvokeOnMainThread(() => { // Call UI methods here }); From a standard C# class: UIApplication.SharedApplicat...

In general, most of the objects you would interact with as a user would tend to be a vector; e.g numeric vector, logical vector. These objects can only take in a single type of variable (a numeric vector can only have numbers inside it). A list would be able to store any type variable in it, making...

# example data test_sentences <- c("The quick brown fox quickly", "jumps over the lazy dog") Let's make the brown fox red: sub("brown","red", test_sentences) #[1] "The quick red fox quickly" "jumps over the lazy dog" Now, ...