Tutorial by Examples: l

flatMap is similar to map. The difference is described by the javadoc as follows: This method is similar to map(Function), but the provided mapper is one whose result is already an Optional, and if invoked, flatMap does not wrap it with an additional Optional. In other words, when you chain a...

The & operator is the parent selector. When used in or as a selector, it is replaced with the full parent selectors (entire sequence of selectors right upto to the topmost level of a nested block) in the final CSS output. It is useful when creating nested rules that require using the parent sel...

Less allows the usage of the parent selector (&) anywhere in a complex selector and thus allows changing styles when the current element is within another element which gives it a different context: For example, in the below code the parent selector is placed at the end and thus it actually be...

In Less you can write much more simple CSS rules and also keep them well formatted, so instead of writing this code: CSS .item { border: 1px solid; padding: 4px; } .item .content, .item .image { float: left; } .item .content { font-size: 12px; } .item .image { width: 300px; }...

The @import statement allows you to insert CSS/Less code from another file into your own CSS/Less file. .foo { background: #900; } @import "my-other-css-file.css"; @import "my-other-less-file.less";

Import the class, which contains the method to be tested. Perform the operation with dummy data. Now compare the result of operation with expected result. - (void)testReverseString{ NSString *originalString = @"hi_my_name_is_siddharth"; NSString *reversedString = [self.someObject ...

- (void)testDoSomethingThatTakesSomeTime{ XCTestExpectation *completionExpectation = [self expectationWithDescription:@"Long method"]; [self.someObject doSomethingThatTakesSomeTimesWithCompletionBlock:^(NSString *result) { XCTAssertEqualObjects(@"result", result, @"Re...

1. For Synchronous methods : - (void)testPerformanceReverseString { NSString *originalString = @"hi_my_name_is_siddharth"; [self measureBlock:^{ [self.someObject reverseString:originalString]; }]; } 2. For Asynchronous methods : - (void)testPerformanceOfAsynch...

If multiple signatures are to be integrated into a PDF, this is done by means of incremental PDF updates (explicitly not by adding multiple SignerInfo structures to a single integrated CMS signature container!): The cryptographic verification of these signatures merely guarantees that the byte ra...

Install PDFTK Server from https://www.pdflabs.com/tools/pdftk-server/ PDFtk Server is a command line tool which can: • Merge PDF Documents or Collate PDF Page Scans • Split PDF Pages into a New Document • Rotate PDF Documents or Pages • Decrypt Input as Necessary (Password Required...

The way Moment uses dates and times is by wrapping the existing Date() object in a moment() object and specifying useful and intuitive methods on this object. Format Dates moment().format('MMMM Do YYYY, h:mm:ss a'); // August 4th 2016, 10:41:45 am moment().format('dddd'); // Th...

This example demonstrates how you can respond to a button click by performing some work on a worker thread and then update the user interface to indicate completion void MyButton_OnClick(object sender, EventArgs args) { Task.Run(() => // Schedule work using the thread pool { ...

C++11 Motivational example When you have a variadic template pack in the template parameters list, like in the following code snippet: template<typename ...Args> void func(Args &&...args) { //... }; The standard library (prior to C++17) offers no direct way to write enable_if...

psycopg2 is the most popular PostgreSQL database adapter that is both lightweight and efficient. It is the current implementation of the PostgreSQL adapter. Its main features are the complete implementation of the Python DB API 2.0 specification and the thread safety (several threads can share t...

var a = new List<int> { 1, 2 }; var b = new List<int> { 2, 1 }; Assert.That (a, Is.EqualTo(b)); // fails Assert.That (a, Is.EquivalentTo(b)); // succeeds

<Image x:Name="MyImage" /> // Show image from web MyImage.Source = new BitmapImage(new Uri("http://your-image-url.com")) // Show image from solution MyImage.Source = new Uri("ms-appx:///your-image-in-solution", UriKind.Absolute) // Show image from file ...

<TextBlock x:Name="MyControl" Text="Hello, world!" /> var rtb = new RenderTargetBitmap(); await rtb.RenderAsync(MyControl); // Render control to RenderTargetBitmap // Get pixels from RTB IBuffer pixelBuffer = await rtb.GetPixelsAsync(); byte[] pixels = ...

IRandomAccessStreamReference bitmap = GetBitmap(); IRandomAccessStreamWithContentType stream = await bitmap.OpenReadAsync(); BitmapDecoder decoder = await BitmapDecoder.CreateAsync(stream); var pixels = await decoder.GetPixelDataAsync(); var outStream = new InMemoryRandomAccessStream(); // Cr...

The IsNull() function accepts two parameters, and returns the second parameter if the first one is null. Parameters: check expression. Any expression of any data type. replacement value. This is the value that would be returned if the check expression is null. The replacement value must be of a...

Since null is not a value, you can't use comparison operators with nulls. To check if a column or variable holds null, you need to use is null: DECLARE @Date date = '2016-08-03' The following statement will select the value 6, since all comparisons with null values evaluates to false or unknown...