Tutorial by Examples: i

[timer invalidate]; timer = nil; This will stop the timer from firing. Must be called from the thread the timer was created in, see Apple's notes: You must send this message from the thread on which the timer was installed. If you send this message from another thread, the input source associ...

[timer fire]; Calling the fire method causes an NSTimer to perform the task it would have usually performed on a schedule. In a non-repeating timer, this will automatically invalidate the timer. That is, calling fire before the time interval is up will result in only one invocation. In a repeat...

Two erlang processes can communicate with each other, wich is also known as message passing. This procedure is asynchronous in the form that the sending process will not halt after sending the message. Sending Messages This can be achieved with the construct Pid ! Message, where Pid is a valid pr...

It is possible to register a process (pid) to a global alias. This can be achieved with the build in register(Alias, Pid) function, where Alias is the atom to access the process as and Pid is the process id. The alias will be globally available! It is very easy to create shared state, wich is usu...

Each process in erlang has a process identifier (Pid) in this format <x.x.x>, x being a natural number. Below is an example of a Pid <0.1252.0> Pid can be used to send messages to the process using 'bang' (!), also Pid can be bounded to a variable, both are shown below MyProcessId =...

Subroutines hold code. Unless specified otherwise, they are globally defined. # Functions do not (have to) specify their argument list sub returns_one { # Functions return the value of the last expression by default # The return keyword here is unnecessary, but helps readability. return 1...

using System.Text.RegularExpressions; string pattern = ":(.*?):"; string lookup = "--:text in here:--"; // Instanciate your regex object and pass a pattern to it Regex rgxLookup = new Regex(pattern, RegexOptions.Singleline, TimeSpan.FromSeconds(1)); // Get the match from y...

using System.Text.RegularExpressions; List<string> found = new List<string>(); string pattern = ":(.*?):"; string lookup = "--:text in here:--:another one:-:third one:---!123:fourth:"; // Instanciate your regex object and pass a pattern to it Regex rgxLookup = ...

class Product(models.Model): name = models.CharField(max_length=20) price = models.FloatField() To Get average price of all products: >>> from django.db.models import Avg, Max, Min, Sum >>> Product.objects.all().aggregate(Avg('price')) # {'price__avg': 124.0} To ...

Subtracting the values of two pointers to an object results in a signed integer *1. So it would be printed using at least the d conversion specifier. To make sure there is a type being wide enough to hold such a "pointer-difference", since C99 <stddef.h> defines the type ptrdiff_t. ...

Most performance tips are very dependent of the current state of JS engines and are expected to be only relevant at a given time. The fundamental law of performance optimization is that you must first measure before trying to optimize, and measure again after a presumed optimization. To measure cod...

The package's official wiki has some essential materials: As a new user, you will want to check out the vignettes, FAQ and cheat sheet. Before asking a question -- here on StackOverflow or anywhere else -- please read the support page. For help on individual functions, the syntax is h...

Go to application/model File name - Home_model.php Inside the file class Home_model extends CI_Model { public $variable; public function __construct() { parent::__construct(); } public function get_data() { $query = $this->db->get('tabl...

Syntax - $this->load->model('model_name'); Practice - $this->load->model('home_model'); If you would like your model assigned to a different object name you can specify it via the second parameter of the loading method: Syntax - $this->load->model('model_name', 'foobar'); ...

Syntax $this->load->model('model_name'); $this->model_name->method_name(); Practice $this->load->model('home_model'); $this->home_model->get_data();

Syntax $array = array( '' => , ); # can pass array $singelData = ''; # something just a filed value $this->load->model('model_name'); $this->model_name->method_name($singelData, $array); Practice $array = array( 'name' => 'codeigniter', 'version' =&g...

public function method_name($single, $array) { echo $single; print_r($array); } Beware with the order which pass from controller to model.

Python makes it extremely intuitive to check if a string contains a given substring. Just use the in operator: >>> "foo" in "foo.baz.bar" True Note: testing an empty string will always result in True: >>> "" in "test" True

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...

Open index.ios.js or index.android.js and delete everything between the <View> </View>. After that, write <Text> Hello World! </Text> and run the emulator. You should see Hello World! written on the screen! Congrats! You've successfully written your first Hello World!