Tutorial by Examples: p

Assumptions: An Oracle JDK has been installed. The JDK was installed to the default directory. Setup steps Open Windows Explorer. In the navigation pane on the left right click on This PC (or Computer for older Windows versions). There is a shorter way without using the explorer in...

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...

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....

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...

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...

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...

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...

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...

2.1.x This example depends on Support Library 23.4.0.+. BottomSheetBehavior is characterized by : Two toolbars with animations that respond to the bottom sheet movements. A FAB that hides when it is near to the "modal toolbar" (the one that appears when you are sliding up). A backdr...

LibGDX has a fairly simple setup, with the help of a simple Java program. You can find the download here. When you startup the application, it will look something like this: Note: This screenshot have been taken on Linux and shows path that differs from a Windows installation. However, the form is...

We can repeat an action some number of times using repeat. CL-USER> (loop repeat 10 do (format t "Hello!~%")) Hello! Hello! Hello! Hello! Hello! Hello! Hello! Hello! Hello! Hello! NIL CL-USER> (loop repeat 10 collect (random 50)) (28 46 44 31 5 33 43 35 37 4)

(loop for i in '(one two three four five six) do (print i)) (loop for i in '(one two three four five six) by #'cddr do (print i)) ;prints ONE THREE FIVE (loop for i on '(a b c d e f g) do (print (length i))) ;prints 7 6 5 4 3 2 1 (loop for i on '(a b c d e f g) by #'cddr ...

(defvar *ht* (make-hash-table)) (loop for (sym num) on '(one 1 two 2 three 3 four 4 five 5 six 6 seven 7 eight 8 nine 9 ten 10) by #'cddr do (setf (gethash sym *ht*) num)) (loop for k being each hash-key of *ht* do (print k)) ; iterate over the keys (loop for k ...

Simple LOOP form without special keywords: (loop forms...) To break out of the loop we can use (return <return value>) ` Some examples: (loop (format t "Hello~%")) ; prints "Hello" forever (loop (print (eval (read)))) ; your very own REPL (loop (let ((r (read))) ...

(loop for s being the symbols in 'cl do (print s)) (loop for s being the present-symbols in :cl do (print s)) (loop for s being the external-symbols in (find-package "COMMON LISP") do (print s)) (loop for s being each external-symbols of "COMMON LISP" ...

(loop for i from 0 to 10 do (print i)) ; prints 0 1 2 3 4 5 6 7 8 9 10 (loop for i from 0 below 10 do (print i)) ; prints 0 1 2 3 4 5 6 7 8 9 10 (loop for i from 10 above 0 do (print i)) ; prints 10 9 8 7 6 5 4 3 2 1 (loop for i from 10 to 0 do (print i)) ; prints noth...

Combining typedef with struct can make code clearer. For example: typedef struct { int x, y; } Point; as opposed to: struct Point { int x, y; }; could be declared as: Point point; instead of: struct Point point; Even better is to use the following typedef struct Poin...