Tutorial by Examples: an

Lists can be created in multiple ways. The recommended way is to use a List literal: var vegetables = ['broccoli', 'cabbage']; The List constructor can be used as well: var fruits = new List(); If you prefer stronger typing, you can also supply a type parameter in one of the following ways:...

Sets can be created via the constructor: var ingredients = new Set(); ingredients.addAll(['gold', 'titanium', 'xenon']);

Maps can be created in multiple ways. Using the constructor, you can create a new map as follow: var searchTerms = new Map(); Types for the key and value can also be defined using generics: var nobleGases = new Map<int, String>(); var nobleGases = <int, String>{}; Maps can othe...

First, some terminology: argument (actual parameter): the actual variable being passed to a function; parameter (formal parameter): the receiving variable that is used in a function. In Python, arguments are passed by assignment (as opposed to other languages, where arguments can be passed by...

In Haskell, it often makes sense not to bother with file handles at all, but simply read or write an entire file straight from disk to memory†, and do all the partitioning/processing of the text with the pure string data structure. This avoids mixing IO and program logic, which can greatly help avoi...

virtualenv is a tool to build isolated Python environments. This program creates a folder which contains all the necessary executables to use the packages that a Python project would need. Installing the virtualenv tool This is only required once. The virtualenv program may be available through yo...

A module is a file containing Python definitions and statements. Function is a piece of code which execute some logic. >>> pow(2,3) #8 To check the built in function in python we can use dir(). If called without an argument, return the names in the current scope. Else, return an alph...

If you've got a session which you wish to destroy, you can do this with session_destroy() /* Let us assume that our session looks like this: Array([firstname] => Jon, [id] => 123) We first need to start our session: */ session_start(); /* We can now remove all the v...

Just execute lsb_release -a. On Debian: $ lsb_release -a No LSB modules are available. Distributor ID: Debian Description: Debian GNU/Linux testing (stretch) Release: testing Codename: stretch On Ubuntu: $ lsb_release -a No LSB modules are available. Distributor ID: Ubun...

NSDictionary *inventory = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:13], @"Mercedes-Benz SLK250", [NSNumber numberWithInt:22], @"Mercedes-Benz E350", [NSNumber numberWithInt:19], @"BMW M3 Coupe", [NSNumber numberWithInt:16],...

To combine an NSArray of NSString into a new NSString: NSArray *yourWords = @[@"Objective-C", @"is", @"just", @"awesome"]; NSString *sentence = [yourWords componentsJoinedByString:@" "]; // Sentence is now: @"Objective-C is just awesome&quo...

If a code module does not contain Option Explicit at the top of the module, then the compiler will automatically (that is, "implicitly") create variables for you when you use them. They will default to variable type Variant. Public Sub ExampleDeclaration() someVariable = 10 ...

If you have a value that never changes in your application, you can define a named constant and use it in place of a literal value. You can use Const only at module or procedure level. This means the declaration context for a variable must be a class, structure, module, procedure, or block, and can...

There are several ways to go about installing matplotlib, some of which will depend on the system you are using. If you are lucky, you will be able to use a package manager to easily install the matplotlib module and its dependencies. Windows On Windows machines you can try to use the pip package ...

Java provides, as part of the utils package, a basic pseudo-random number generator, appropriately named Random. This object can be used to generate a pseudo-random value as any of the built-in numerical datatypes (int, float, etc). You can also use it to generate a random Boolean value, or a random...

The method nextInt(int bound) of Random accepts an upper exclusive boundary, i.e. a number that the returned random value must be less than. However, only the nextInt method accepts a bound; nextLong, nextDouble etc. do not. Random random = new Random(); random.nextInt(1000); // 0 - 999 int num...

Getting ("a", 1) ^. _1 -- returns "a" ("a", 1) ^. _2 -- returns 1 Setting ("a", 1) & _1 .~ "b" -- returns ("b", 1) Modifying ("a", 1) & _2 %~ (+1) -- returns ("a", 2) both Traversal (1, 2) & bot...

Consider we have a class Animal which has a child class Dog class Animal { public Animal() { Console.WriteLine("In Animal's constructor"); } } class Dog : Animal { public Dog() { Console.WriteLine("In Dog's constructor"); } ...

First of all, implement your view holder: implements View.OnClickListener, View.OnLongClickListener Then, register the listeners as follows: itemView.setOnClickListener(this); itemView.setOnLongClickListener(this); Next, override the listeners as follows: @Override public void onClick(Vie...

Properties are members of an object. Each named property is a pair of (name, descriptor). The name is a string that allows access (using the dot notation object.propertyName or the square brackets notation object['propertyName']). The descriptor is a record of fields defining the bevahiour of the pr...