Tutorial by Examples: c

Code snippet: import java.util.Set; public class ThreadStatus { public static void main(String args[]) throws Exception { for (int i = 0; i < 5; i++){ Thread t = new Thread(new MyThread()); t.setName("MyThread:" + i); t.start(); ...

Sometimes you need to fetch data asynchronously before passing it to a child component to use. If the child component tries to use the data before it has been received, it will throw an error. You can use ngOnChanges to detect changes in a components' @Inputs and wait until they are defined before a...

We consume rest API as a JSON format and then unmarshal it to a POJO. Jackson’s org.codehaus.jackson.map.ObjectMapper “just works” out of the box and we really don’t do anything in most cases. But sometimes we need custom deserializer to fulfill our custom needs and this tutorial will guide you thro...

If you need to add proxy of your network in a reboot-persistent way, edit: sudo vim /etc/environment Press i and after the row with PATH variable insert: http_proxy=http://<proxy_server>:<port>/ https_proxy=http://<proxy_server>:<port>/ ftp_proxy=http://<proxy_serve...

If you want to show active network interfaces, type: ifconfig If you want to show also network interfaces that are down, type: ifconfig -a

You could use ethtool, but they are not going to be reboot persistent. If you want to achieve this, edit the following file: sudo vim /etc/network/interfaces And edit the file with needed informations: auto <interface_name> iface <interface_name> inet static address <ip_addres...

Using the class below, we can connect to Exchange and then set a specific user's out of office settings with UpdateUserOof: using System; using System.Web.Configuration; using Microsoft.Exchange.WebServices.Data; class ExchangeManager { private ExchangeService Service; public Exch...

The function np.loadtxt can be used to read csv-like files: # File: # # Col_1 Col_2 # 1, 1 # 2, 4 # 3, 9 np.loadtxt('/path/to/dir/csvlike.txt', delimiter=',', comments='#') # Output: # array([[ 1., 1.], # [ 2., 4.], # [ 3., 9.]]) The same file could be read ...

# example data DT = as.data.table(mtcars, keep.rownames = TRUE) To rearrange the order of columns, use setcolorder. For example, to reverse them setcolorder(DT, rev(names(DT))) This costs almost nothing in terms of performance, since it is just permuting the list of column pointers in the da...

# example data DT = as.data.table(mtcars, keep.rownames = TRUE) To rename a column (while keeping its data the same), there is no need to copy the data to a column with a new name and delete the old one. Instead, we can use setnames(DT, "mpg_sq", "mpq_squared") to modify ...

# example data DT = data.table(iris) To modify factor levels by reference, use setattr: setattr(DT$Species, "levels", c("set", "ver", "vir") # or DT[, setattr(Species, "levels", c("set", "ver", "vir"))] The sec...

# example data set.seed(1) n = 1e7 ng = 1e4 DT = data.table( g1 = sample(ng, n, replace=TRUE), g2 = sample(ng, n, replace=TRUE), v = rnorm(n) ) Matching on one column After the first run of a subsetting operation with == or %in%... system.time( DT[ g1 %in% 1:100] )...

Consider a grid working on some task, e.g. a parallel reduction. Initially, each block can do its work independently, producing some partial result. At the end however, the partial results need to be combined and merged together. A typical example is a reduction algorithm on a big data. A typica...

Tuples support the following build-in functions Comparison If elements are of the same type, python performs the comparison and returns the result. If elements are different types, it checks whether they are numbers. If numbers, perform comparison. If either element is a number, then the other...

Introduction The PHPUnit Manual describes mocking as such: The practice of replacing an object with a test double that verifies expectations, for instance asserting that a method has been called, is referred to as mocking. So instead of stubbing out code, an observer is created that not onl...

// application/controllers/Company_controller.php <?php if(!defined('BASEPATH')) exit('No direct script access allowed'); class Company_controller extends CI_Controller { public function __construct() { parent::__construct(); $this->load->model('companies_mo...

If a void* value is converted to a pointer to object type, T*, but is not properly aligned for T, the resulting pointer value is unspecified. Example: // Suppose that alignof(int) is 4 int x = 42; void* p1 = &x; // Do some pointer arithmetic... void* p2 = static_cast<char*>(p1) + 2; ...

Batch file command line arguments are parameter values submitted when starting the batch. They should be enclosed in quotes if they contain spaces. In a running batch file, the arguments are used for various purposes, i.e. redirection to :labels, setting variables, or running commands. The argument...

When more than 9 arguments are supplied, the shift [/n] command can be used, where /n means start at the nth argument, n is between zero and eight. Looping through arguments: :args set /a "i+=1" set arg!i!=%~1 call echo arg!i! = %%arg!i!%% shift goto :args Note, in the above exam...

Let's create an Enumerator for Fibonacci numbers. fibonacci = Enumerator.new do |yielder| a = b = 1 loop do yielder << a a, b = b, a + b end end We can now use any Enumerable method with fibonacci: fibonacci.take 10 # => [1, 1, 2, 3, 5, 8, 13, 21, 34, 55]