Tutorial by Examples: alv

Declaration and usage. // a is const int, so it can't be changed const int a = 15; a = 12; // Error: can't assign new value to const variable a += 1; // Error: can't assign new value to const variable Binding of references and pointers int &b = a; // Error: ca...

reference : NetConnection , NetStream , Video related topics : Working with Sound Basic example of playing an external video file (FLV, MP4, F4V). Code will also play M4A audio files. var nc:NetConnection = new NetConnection(); nc.connect(null); var ns:NetStream = new NetStream(nc); va...

int a; std::cout << a; // Undefined behavior! This results in undefined behavior, because a is uninitialised. It is often, incorrectly, claimed that this is because the value is "indeterminate", or "whatever value was in that memory location before". However, it is th...

DECLARE @Var1 INT = 5, @Var2 NVARCHAR(50) = N'Hello World', @Var3 DATETIME = GETDATE()

String to a primitive numeric type or a numeric wrapper type: Each numeric wrapper class provides a parseXxx method that converts a String to the corresponding primitive type. The following code converts a String to an int using the Integer.parseInt method: String string = "59"; int p...

It is possible, inside a closure, to use an external variable with the special keyword use. For instance: <?php $quantity = 1; $calculator = function($number) use($quantity) { return $number + $quantity; }; var_dump($calculator(2)); // Shows "3" You can go further by ...

The .format() method can interpret a number in different formats, such as: >>> '{:c}'.format(65) # Unicode character 'A' >>> '{:d}'.format(0x0a) # base 10 '10' >>> '{:n}'.format(0x0a) # base 10 using current locale for separators '10' Format integers to d...

When you implement java.io.Serializable interface to make a class serializable, the compiler looks for a static final field named serialVersionUID of type long. If the class doesn't have this field declared explicitly then the compiler will create one such field and assign it with a value which come...

Sometimes a RecyclerView will need to use several types of Views to be displayed in the list shown in the UI, and each View needs a different layout xml to be inflated. For this issue, you may use different ViewHolders in single Adapter, by using a special method in RecyclerView - getItemViewType(i...

The awk language does not directly support variables local to functions. It is however easy emulate them by adding extra arguments to functions. It is traditional to prefix these variables by a _ to indicate that they are not actual parameters. We illustrate this technique with the definition of a...

Thus these variables will use dynamic binding. (defparameter count 0) ;; All uses of count will refer to this one (defun handle-number (number) (incf count) (format t "~&~d~%" number)) (dotimes (count 4) ;; count is shadowed, but still special (handle-number coun...

Mostly you will use "normal variables": set(VAR TRUE) set(VAR "main.cpp") set(VAR1 ${VAR2}) But CMake does also know global "cached variables" (persisted in CMakeCache.txt). And if normal and cached variables of the same name exist in the current scope, normal var...

The scope outside of any function or class is the global scope. When a PHP script includes another (using include or require) the scope remains the same. If a script is included outside of any function or class, it's global variables are included in the same global scope, but if a script is include...

Superglobal variables are defined by PHP and can always be used from anywhere without the global keyword. <?php function getPostValue($key, $default = NULL) { // $_POST is a superglobal and can be used without // having to specify 'global $_POST;' if (isset($_POST[$key])) { ...

To declare a single instance of a variable which is accessible in different source files, it is possible to make it in the global scope with keyword extern. This keyword says the compiler that somewhere in the code there is a definition for this variable, so it can be used everywhere and all write/r...

//Swift let initialScreen = storyboard.instantiateInitialViewController() //Objective-c UIViewController *initailScreen = [storyboard instantiateInitialViewController];

Javascript engines first look for variables within the local scope before extending their search to larger scopes. If the variable is an indexed value in an array, or an attribute in an associative array, it will first look for the parent array before it finds the contents. This has implications wh...

returnType (^blockName)(parameterType1, parameterType2, ...) = ^returnType(argument1, argument2, ...) {...}; float (^square)(float) = ^(float x) {return x*x;}; square(5); // resolves to 25 square(-7); // resolves to 49 Here's an example with no return and no parameters: NSMutableDicti...

Local variables (unlike the other variable classes) do not have any prefix local_variable = "local" p local_variable # => local Its scope is dependent on where it has been declared, it can not be used outside the "declaration containers" scope. For example, if a local va...

Global variables have a global scope and hence, can be used everywhere. Their scope is not dependent on where they are defined. A variable will be considered global, when prefixed with a $ sign. $i_am_global = "omg" class Dinosaur def instance_method p "global vars ca...