Tutorial by Examples: chai

The left-hand operand must be nullable, while the right-hand operand may or may not be. The result will be typed accordingly. Non-nullable int? a = null; int b = 3; var output = a ?? b; var type = output.GetType(); Console.WriteLine($"Output Type :{type}"); Console.WriteLine($&q...
Many LINQ functions both operate on an IEnumerable<TSource> and also return an IEnumerable<TResult>. The type parameters TSource and TResult may or may not refer to the same type, depending on the method in question and any functions passed to it. A few examples of this are public stat...
The then method of a promise returns a new promise. const promise = new Promise(resolve => setTimeout(resolve, 5000)); promise // 5 seconds later .then(() => 2) // returning a value from a then callback will cause // the new promise to resolve with this value .then...
You can compare multiple items with multiple comparison operators with chain comparison. For example x > y > z is just a short form of: x > y and y > z This will evaluate to True only if both comparisons are True. The general form is a OP b OP c OP d ... Where OP represents ...
The pipe operator, %>%, is used to insert an argument into a function. It is not a base feature of the language and can only be used after attaching a package that provides it, such as magrittr. The pipe operator takes the left-hand side (LHS) of the pipe and uses it as the first argument of the ...
Method Chaining is a technique explained in Martin Fowler's book Domain Specific Languages. Method Chaining is summarized as Makes modifier methods return the host object, so that multiple modifiers can be invoked in a single expression. Consider this non-chaining/regular piece of code (ported...
Pipes may be chained. <p>Today is {{ today | date:'fullDate' | uppercase}}.</p>
You can use Optional Chaining in order to call a method, access a property or subscript an optional. This is done by placing a ? between the given optional variable and the given member (method, property or subscript). struct Foo { func doSomething() { print("Hello World!") ...
In the process of handling an exception, you may want to raise another exception. For example, if you get an IOError while reading from a file, you may want to raise an application-specific error to present to the users of your library, instead. Python 3.x3.0 You can chain exceptions to show how t...
This design pattern is useful for generating a sequence of asynchronous actions from a list of elements. There are two variants : the "then" reduction, which builds a chain that continues as long as the chain experiences success. the "catch" reduction, which builds a chain t...
Alamofire.request(.GET, "https://httpbin.org/get") .validate() .responseString { response in print("Response String: \(response.result.value)") } .responseJSON { response in print("Response JSON: \(response.result.value)") ...
A Value Converter can be used alongside other value converters and you can infinitely chain them using the | pipe separator. ${myString | toUppercase | removeCharacters:'&,%,-,+' | limitTo:25} The above theoretical example firstly applies toUppercase which capitalizes our string. Then it app...
When an extension method returns a value that has the same type as its this argument, it can be used to "chain" one or more method calls with a compatible signature. This can be useful for sealed and/or primitive types, and allows the creation of so-called "fluent" APIs if the me...
Method chaining is a programming strategy that simplifies your code and beautifies it. Method chaining is done by ensuring that each method on an object returns the entire object, instead of returning a single element of that object. For example: function Door() { this.height = ''; this.w...
Working Source - https://github.com/benhysell/V.TouchIdExample Long form description - http://benjaminhysell.com/archive/2014/11/authentication-in-xamarin-ios-with-touch-id-or-passcode/ //Simple View with a switch to enable / disable Touch ID and //a button to invoke authentication /// <s...
Stream is especially useful when you want to run multiple operations on a collection. This is because Stream is lazy and only does one iteration (whereas Enum would do multiple iterations, for example). numbers = 1..100 |> Stream.map(fn(x) -> x * 2 end) |> Stream.filter(fn(x) -> rem(x...
The when-statement is an alternative to an if-statement with multiple else-if-branches: when { str.length == 0 -> print("The string is empty!") str.length > 5 -> print("The string is short!") else -> print("The string is long!") ...
Any lodash collection method has two syntaxes. Without chaining: var arr1 = [10, 15, 20, 25, 30, 15, 25, 35]; var arr2 = _.filter(arr1, function(item){ return item % 10 === 5 }); // arr2 now contains [15, 25, 15, 25, 35] var arr3 = _.uniq(arr2); // arr3 now contains [15, 25, 35] var arr...
.message color: white background: black .message-important @extend .message font-weight: bold .message-error @extend .message-important font-style: italic This code causes .message-error to extend from .message-important, which means that it will contain code from both .me...
Coroutines can yield inside themselves, and wait for other coroutines. So, you can chain sequences - "one after the other". This is very easy, and is a basic, core, technique in Unity. It's absolutely natural in games that certain things have to happen "in order". Almost every...

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