Tutorial by Examples: ti

Some example cases when the result is an optional. var result: AnyObject? = someMethod() switch result { case nil: print("result is nothing") case is String: print("result is a String") case _ as Double: print("result is not nil, any value that is a Dou...

Before C++17, having pointers with a value of nullptr commonly represented the absence of a value. This is a good solution for large objects that have been dynamically allocated and are already managed by pointers. However, this solution does not work well for small or primitive types such as int, w...

Before C++17, a function typically represented failure in one of several ways: A null pointer was returned. e.g. Calling a function Delegate *App::get_delegate() on an App instance that did not have a delegate would return nullptr. This is a good solution for objects that have been dynamicall...

In most examples, the class naming convention is used to define an Aurelia Custom Element. However, Aurelia also provides a decorator that can be used to decorate a class. The class is again treated as a custom element by Aurelia then. The value supplied to the decorator becomes the name of the cus...

You can declare multiple constants within the same const block: const ( Alpha = "alpha" Beta = "beta" Gamma = "gamma" ) And automatically increment constants with the iota keyword: const ( Zero = iota // Zero == 0 One // One == 1...

Assert.That(actual, Is.EqualTo(expected));

Invoking a function as a method of an object the value of this will be that object. var obj = { name: "Foo", print: function () { console.log(this.name) } } We can now invoke print as a method of obj. this will be obj obj.print(); This will thus log: Foo...

Invoking a function as an anonymous function, this will be the global object (self in the browser). function func() { return this; } func() === window; // true 5 In ECMAScript 5's strict mode, this will be undefined if the function is invoked anonymously. (function () { "use...

When a function is invoked as a constructor with the new keyword this takes the value of the object being constructed function Obj(name) { this.name = name; } var obj = new Obj("Foo"); console.log(obj); This will log { name: "Foo" }

6 When using arrow functions this takes the value from the enclosing execution context's this (that is, this in arrow functions has lexical scope rather than the usual dynamic scope). In global code (code that doesn't belong to any function) it would be the global object. And it keeps that way, eve...

The apply and call methods in every function allow it to provide a custom value for this. function print() { console.log(this.toPrint); } print.apply({ toPrint: "Foo" }); // >> "Foo" print.call({ toPrint: "Foo" }); // >> "Foo" You mig...

The bind method of every function allows you to create new version of that function with the context strictly bound to a specific object. It is specially useful to force a function to be called as a method of an object. var obj = { foo: 'bar' }; function foo() { return this.foo; } fooOb...

Normally your tests should be created in such a way that execution order is no concern. However there is always going to be an edge case were you need to break that rule. The one scenario I came across was with R.NET whereby in a given process you can only initialize one R Engine and once disposed ...

let sel = document.getSelection(); sel.removeAllRanges();

let sel = document.getSelection(); let text = sel.toString(); console.log(text); // logs what the user selected Alternatively, since the toString member function is called automatically by some functions when converting the object to a string, you don't always have to call it yourself. console...

To create a custom template we first need to create php file in a theme directory. You can name it almost any way you want. For this example we will create example.php One and only thing we need to define inside our example.php, to be recognized by WordPress as a template, is template name. We do t...

Some attributes are directly accessible as properties of the element (e.g. alt, href, id, title and value). var a = document.querySelector("a"), url = a.href; Other attributes, including data-attributes can be accessed as follows: var a = document.querySelector("a"), ...

Values can be given names using let: # let a = 1;; val a : int = 1 You can use similar syntax to define a function. Just provide additional parameters for the arguments. # let add arg1 arg2 = arg1 + arg2;; val add : int -> int -> int = <fun> We can call it like this: # add 1...

The function keyword automatically has pattern matching when you define the body of your function. Observe it below: # let foo = function 0 -> "zero" | 1 -> "one" | 2 -> "couple" | 3 -> "few" | _ -> "many";; val foo : int -&gt...

3.0 let string = "My fantastic string" var index = string.startIndex while index != string.endIndex { print(string[index]) index = index.successor() } Note: endIndex is after the end of the string (i.e. string[string.endIndex] is an error, but string[string.startIndex] i...