Tutorial by Examples: gas
import UIKit
import WebKit
class ViewController: UIViewController, UISearchBarDelegate, WKNavigationDelegate, WKUIDelegate {
var searchbar: UISearchBar! //All web-browsers have a search-bar.
var webView: WKWebView! //The WKWebView we'll use.
var toolbar: UIToolbar! //Toolb...
1.8
Run:
$ git mv old/path/to/module new/path/to/module
1.8
Edit .gitmodules and change the path of the submodule appropriately, and put it in the index with git add .gitmodules.
If needed, create the parent directory of the new location of the submodule (mkdir -p new/path/to).
M...
genRandom creates a stream of random numbers that has a one in four chance of terminating each time it's called.
def genRandom: Stream[String] = {
val random = scala.util.Random.nextFloat()
println(s"Random value is: $random")
if (random < 0.25) {
Stream.empty[String]
...
Purpose
Use the CREATE SEQUENCE statement to create a sequence, which is a database object from which multiple users may generate unique integers. You can use sequences to automatically generate primary key values.
When a sequence number is generated, the sequence is incremented, independent of th...
NSAttributedString (and its mutable sibling NSMutableAttributedString) allows you to create strings that are complex in their appearance to the user.
A common application is to use this to display a string and adding custom kerning / letter-spacing.
This would be achieved as follows (where label ...
If you find that you have multiple servers that need to share session state, storing it in the ASP.NET process memory will not work. For example you may deploy into a web-farm environment with a load balancer that distributes requests in a round-robin fashion. In this environment a single user's req...
Example of calling an extension method as an extension and as a regular method.
public Class MyClass
Sub Main()
'Extension called directly on the object.
Dim Version = Assembly.GetExecutingAssembly.GetVersionFromAssembly()
'Called as a regular method.
...
main.component.ts
import {Component} from "@angular/core";
@Component({
selector: "main",
template: `
<StackLayout>
<TextField hint="some text"></TextField>
<Button text="Click me" class="btn">...
std::vector<std::string> split(const std::string &str, std::string regex)
{
std::regex r{ regex };
std::sregex_token_iterator start{ str.begin(), str.end(), r, -1 }, end;
return std::vector<std::string>(start, end);
}
split("Some string\t with whitespace &...
The format of the struct statement is this:
struct [structure tag]
{
member definition;
member definition;
...
member definition;
} [one or more structure variables];
Example: declare the ThreeFloats structure:
typedef struct {
float x, y, z;
} ThreeFloats;
@inter...
Using the
System.String.Contains you can find out if a particular string exists within a string. The method returns a boolean, true if the string exists else false.
string s = "Hello World";
bool stringExists = s.Contains("ello"); //stringExists =true as the string contains t...
Using the System.String.Replace method, you can replace part of a string with another string.
string s = "Hello World";
s = s.Replace("World", "Universe"); // s = "Hello Universe"
All the occurrences of the search string are replaced:
string s = "He...
Use the System.String.Split method to return a string array that contains substrings of the original string, split based on a specified delimiter:
string sentence = "One Two Three Four";
string[] stringArray = sentence.Split(' ');
foreach (string word in stringArray)
{
Console.W...
You can render the contents of an SVG file as an image within an HTML document using an <img> tag. For example:
<img src="my_svg_file.svg" alt="Image description">
The dimensions of the image will, by default, display according to the width and height properties s...
Disclaimer: In no way does this example advocate the use of singletons. Singletons are to be used with a lot of care.
In PHP there is quite a standard way of implementing a singleton:
public class Singleton {
private $instance;
private function __construct() { };
public function...
# 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...
A string can be written to a file with an instance of the File class.
file = File.new('tmp.txt', 'w')
file.write("NaNaNaNa\n")
file.write('Batman!\n')
file.close
The File class also offers a shorthand for the new and close operations with the open method.
File.open('tmp.txt', 'w') ...
You can call static methods like this:
(System/currentTimeMillis)
;;=> 1469493415265
Or pass in arguments, like this:
(System/setProperty "foo" "42")
;;=> nil
(System/getProperty "foo")
;;=> "42"
The easiest way to create a custom data type in Haskell is to use the data keyword:
data Foo = Bar | Biz
The name of the type is specified between data and =, and is called a type constructor. After = we specify all value constructors of our data type, delimited by the | sign. There is a rule in...
A sprite sheet by definition is a bitmap that contains a certain animation. Old games use grid type sprite sheet, that is, every frame occupies an equal region, and frames are aligned by the edges to form a rectangle, probably with some spaces unoccupied. Later, in order to minimize the bitmap size,...
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