Tutorial by Examples: g

git bisect allows you to find which commit introduced a bug using a binary search. Start by bisecting a session by providing two commit references: a good commit before the bug, and a bad commit after the bug. Generally, the bad commit is HEAD. # start the git bisect session $ git bisect start ...

To explicitly declare variables in VBA, use the Dim statement, followed by the variable name and type. If a variable is used without being declared, or if no type is specified, it will be assigned the type Variant. Use the Option Explicit statement on first line of a module to force all variables t...

Serialization with Gson is easy and will output correct JSON. public class Employe { private String firstName; private String lastName; private int age; private BigDecimal salary; private List<String> skills; //getters and setters } (Serialization) ...

In order to create a new Android HTTP Client HttpURLConnection, call openConnection() on a URL instance. Since openConnection() returns a URLConnection, you need to explicitly cast the returned value. URL url = new URL("http://example.com"); HttpURLConnection connection = (HttpURLConnect...

URL url = new URL("http://example.com"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); try { BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream())); // read the input stream // in this case, I simply read t...

URL url = new URL("http://example.com"); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); try { BufferedReader br = new BufferedReader(new InputStreamReader(connection.getInputStream())); // use a string builder to bufferize the response body //...

SQL injection is a kind of attack that allows a malicious user to modify the SQL query, adding unwanted commands to it. For example, the following code is vulnerable: // Do not use this vulnerable code! $sql = 'SELECT name, email, user_level FROM users WHERE userID = ' . $_GET['user']; $conn->...

// Create a block with an asynchronous action var block = new ActionBlock<string>(async hostName => { IPAddress[] ipAddresses = await Dns.GetHostAddressesAsync(hostName); Console.WriteLine(ipAddresses[0]); }); block.Post("google.com"); // Post items to the block's ...

var httpClient = new HttpClient(); // Create a block the accepts a uri and returns its contents as a string var downloaderBlock = new TransformBlock<string, string>( async uri => await httpClient.GetStringAsync(uri)); // Create a block that accepts the content and prints it to t...

jQuery makes handling jSON responses painless, but a bit more work is required when a given request wishes you to send data in JSON format: $.ajax("/json-consuming-route", { data: JSON.stringify({author: {name: "Bullwinkle J. Moose", ...

Requirements: 64-bit version of Windows 7 or higher on a machine which supports Hardware Virtualization Technology, and it is enabled. While the docker binary can run natively on Windows, to build and host containers you need to run a Linux virtual machine on the box. 1.12.0 Since version 1.12 y...

Docker is supported on the following 64-bit versions of Ubuntu Linux: Ubuntu Xenial 16.04 (LTS) Ubuntu Wily 15.10 Ubuntu Trusty 14.04 (LTS) Ubuntu Precise 12.04 (LTS) A couple of notes: The following instructions involve installation using Docker packages only, and this ensures obtaining...

HandleFunc registers the handler function for the given pattern in the server mux (router). You can pass define an anonymous function, as we have seen in the basic Hello World example: http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) { fmt.Fprintln(w, "Hello, w...

The simplest way to create an error is by using the errors package. errors.New("this is an error") If you want to add additional information to an error, the fmt package also provides a useful error creation method: var f float64 fmt.Errorf("error with some additional informatio...

In Go, an error is represented by any value that can describe itself as string. Any type that implement the built-in error interface is an error. // The error interface is represented by a single // Error() method, that returns a string representation of the error type error interface { Erro...

In Go you don't raise an error. Instead, you return an error in case of failure. // This method can fail func DoSomething() error { // functionThatReportsOK is a side-effecting function that reports its // state as a boolean. NOTE: this is not a good practice, so this example // tur...

In Go errors can be returned from a function call. The convention is that if a method can fail, the last returned argument is an error. func DoAndReturnSomething() (string, error) { if os.Getenv("ERROR") == "1" { return "", errors.New("The method fai...

A Table View is a list of rows that can be selected. Each row is populated from a data source. This example creates a simple table view in which each row is a single line of text. Add a UITableView to your Storyboard Although there are a number of ways to create a UITableView, one of the easiest...

Boilerplate code example override func viewDidLoad() { super.viewDidLoad() let myView = UIView() myView.backgroundColor = UIColor.blueColor() myView.translatesAutoresizingMaskIntoConstraints = false view.addSubview(myView) // Add constraints code here // ... ...

Let's take an example of adding a value to a range (as it could be done in a loop for example): 3+1:5 Gives: [1] 4 5 6 7 8 This is because the range operator : has higher precedence than addition operator +. What happens during evaluation is as follows: 3+1:5 3+c(1, 2, 3, 4, 5) expansio...