Tutorial by Examples: ch

Consider the following block of code. try { using (var disposable = new MyDisposable()) { throw new Exception("Couldn't perform operation."); } } catch (Exception ex) { Console.WriteLine(ex.Message); } class MyDisposable : IDisposable { public vo...

Prerequisites In order to run Elasticsearch, a Java Runtime Environment (JRE) is required on the machine. Elasticsearch requires Java 7 or higher and recommends Oracle JDK version 1.8.0_73. Install Oracle Java 8 sudo add-apt-repository -y ppa:webupd8team/java sudo apt-get update echo "or...

Use charAt() to get a character at the specified index in the string. var string = "Hello, World!"; console.log( string.charAt(4) ); // "o" Alternatively, because strings can be treated like arrays, use the index via bracket notation. var string = "Hello, World!";...

You can use the Substring method to get any number of characters from a string at any given location. However, if you only want a single character, you can use the string indexer to get a single character at any given index like you do with an array: string s = "hello"; char c = s[1]; //...

defmodule Math do # We start of by passing the sum/1 function a list of numbers. def sum(numbers) do do_sum(numbers, 0) end # Recurse over the list when it contains at least one element. # We break the list up into two parts: # head: the first element of the list # ta...

You can create a new branch and switch to it using git checkout -b AP-57 After you use git checkout to create a new branch, you will need to set that upstream origin to push to using git push --set-upstream origin AP-57 After that, you can use git push while you are on that branch.

When you have an input with well defined boundaries and are expecting more than one match in your string, you have two options: Using lazy quantifiers; Using a negated character class. Consider the following: You have a simple templating engine, you want to replace substrings like $[foo] whe...

[^0-9a-zA-Z] This will match all characters that are neither numbers nor letters (alphanumerical characters). If the underscore character _ is also to be negated, the expression can be shortened to: [^\w] Or: \W In the following sentences: Hi, what's up? I can't wait for 2017!...

[^0-9] This will match all characters that are not ASCII digits. If Unicode digits are also to be negated, the following expression can be used, depending on your flavor/language settings: [^\d] This can be shortened to: \D You may need to enable Unicode character properties support expl...

To get version 5394 use: svn co --revision r5394 https://svn.example.com/svn/MyRepo/MyProject/trunk Or the shorter version: svn co -r 5394 https://svn.example.com/svn/MyRepo/MyProject/trunk Or by using pegged revisions: svn co https://svn.example.com/svn/MyRepo/MyProject/trunk@5394 If al...

private static final int REQUEST_ENABLE_BT = 1; // Unique request code BluetoothAdapter mBluetoothAdapter; // ... if (!mBluetoothAdapter.isEnabled()) { Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(enableBtIntent, REQUEST_ENABLE_B...

Support vector machines is a family of algorithms attempting to pass a (possibly high-dimension) hyperplane between two labelled sets of points, such that the distance of the points from the plane is optimal in some sense. SVMs can be used for classification or regression (corresponding to sklearn.s...

Sometimes repos will have commits that only adjust whitespace, for example fixing indentation or switching between tabs and spaces. This makes it difficult to find the commit where the code was actually written. git blame -w will ignore whitespace-only changes to find where the line really came fr...

The For Each loop construct is ideal for iterating all elements of a collection. Public Sub IterateCollection(ByVal items As Collection) 'For Each iterator must always be variant Dim element As Variant For Each element In items 'assumes element can be converted to a stri...

vagrant up --provider hyperv

vagrant up --provider docker

vagrant up --provider vmware_fusion

vagrant up --provider vmware_workstation

vagrant up --provider virtualbox VirtualBox is the default provider for a vanilla Vagrant setup.

NSString *testString1 = @"(555) 123-5678"; NSString *testString2 = @"not a phone number"; NSError *error = nil; NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern:@"^\\(\\d{3}\\) \\d{3}\\-\\d{4}$" ...