Tutorial by Examples: alv

package com.example; import android.os.Bundle; import android.support.annotation.Nullable; import android.util.Log; import android.view.View; import android.view.ViewTreeObserver; public class ExampleActivity extends Activity { @Override protected void onCreate(@Nullable final ...

// Obtain an instance of JavaScript engine ScriptEngineManager manager = new ScriptEngineManager(); ScriptEngine engine = manager.getEngineByName("nashorn"); // Define a global variable engine.put("textToPrint", "Data defined in Java."); // Print the global var...

min(7,2,1,5) # Output: 1 max(7,2,1,5) # Output: 7

In Python, variables inside functions are considered local if and only if they appear in the left side of an assignment statement, or some other binding occurrence; otherwise such a binding is looked up in enclosing functions, up to the global scope. This is true even if the assignment statement is ...

Local variables are defined within a function, method, or closure: func printSomething() { let localString = "I'm local!" print(localString) } func printSomethingAgain() { print(localString) // error } Global variables are defined outside of a function, method, or c...

Tuples can be decomposed into individual variables with the following syntax: let myTuple = (name: "Some Name", age: 26) let (first, second) = myTuple print(first) // "Some Name" print(second) // 26 This syntax can be used regardless of if the tuple has unnamed properti...

Background CSS colors may also be represented as a hex triplet, where the members represent the red, green and blue components of a color. Each of these values represents a number in the range of 00 to FF, or 0 to 255 in decimal notation. Uppercase and/or lowercase Hexidecimal values may be used (i...

We can illustrate this problem with the following pseudo-code function foo() { global $bob; $bob->doSomething(); } Your first question here is an obvious one Where did $bob come from? Are you confused? Good. You've just learned why globals are confusing and considered a bad p...

Modal views completely capture the user’s attention until a task is complete. iOS clarifies this to users by dimming and disabling all other content when a modal view, such as an alert or popover, is visible. An app that implements a custom modal interface needs to hint to VoiceOver that this view d...

Modules can have a special variable named __all__ to restrict what variables are imported when using from mymodule import *. Given the following module: # mymodule.py __all__ = ['imported_by_star'] imported_by_star = 42 not_imported_by_star = 21 Only imported_by_star is imported when usi...

If a name is bound inside a function, it is by default accessible only within the function: def foo(): a = 5 print(a) # ok print(a) # NameError: name 'a' is not defined Control flow constructs have no impact on the scope (with the exception of except), but accessing variable that w...

Use of global variables is generally discouraged. It makes your program more difficult to understand, and harder to debug. But sometimes using a global variable is acceptable. global.h #ifndef GLOBAL_DOT_H /* This is an "include guard" */ #define GLOBAL_DOT_H /** * This tells ...

With Blade, you can also include partial views (called 'partials') directly into a page like so: @include('includes.info', ['title' => 'Information Station']) The code above will include the view at 'views/includes/info.blade.php'. It will also pass in a variable $title having value 'Informat...

With virtual member functions: #include <iostream> struct X { virtual void f() { std::cout << "X::f()\n"; } }; struct Y : X { // Specifying virtual again here is optional // because it can be inferred from X::f(). virtual void f() { std::cout <&lt...

Python 3.x3.0 Python 3 added a new keyword called nonlocal. The nonlocal keyword adds a scope override to the inner scope. You can read all about it in PEP 3104. This is best illustrated with a couple of code examples. One of the most common examples is to create function that can increment: def c...

Alamofire.request(.GET, "https://httpbin.org/get", parameters: ["foo": "bar"]) .validate(statusCode: 200..<300) .validate(contentType: ["application/json"]) .response { response in print(response) }

C++11 introduced final specifier which forbids method overriding if appeared in method signature: class Base { public: virtual void foo() { std::cout << "Base::Foo\n"; } }; class Derived1 : public Base { public: // Overriding Base::foo void foo() f...

A bi-directional value converter utilizes two methods in your Value Converter class: toView and fromView these methods are aptly named to signify which direction the data is flowing. In our example we will be creating a prepend Value Converter which will make sure that an amount entered in our app ...

It is possible to define local variables inside a function to reduce code repetition give name to subexpressions reduce the amount of passed arguments. The construct for this is let ... in .... bigNumbers = let allNumbers = [1..100] isBig number = ...

set(my_variable "the value is a string") By default, a local variable is only defined in the current directory and any subdirectories added through the add_subdirectory command. To extend the scope of a variable there are two possibilities: CACHE it, which will make it globally av...