Tutorial by Examples: o

This code example creates a TCP client, sends "Hello World" over the socket connection, and then writes the server response to the console before closing the connection. // Declare Variables string host = "stackoverflow.com"; int port = 9999; int timeout = 5000; // Create ...

public async Task<Product> GetProductAsync(string productId) { using (_db) { return await _db.QueryFirstOrDefaultAsync<Product>("usp_GetProduct", new { id = productId }, commandType: CommandType.StoredProcedure); } }

With this example, we will see how to load a color image from disk and display it using OpenCV's built-in functions. We can use the C/C++, Python or Java bindings to accomplish this. In C++: #include <opencv2/core.hpp> #include <opencv2/highgui.hpp> #include <iostream> usi...

prop_evenNumberPlusOneIsOdd :: Integer -> Property prop_evenNumberPlusOneIsOdd x = even x ==> odd (x + 1) If you want to check that a property holds given that a precondition holds, you can use the ==> operator. Note that if it's very unlikely for arbitrary inputs to match the precondit...

A try/catch block is used to catch exceptions. The code in the try section is the code that may throw an exception, and the code in the catch clause(s) handles the exception. #include <iostream> #include <string> #include <stdexcept> int main() { std::string str("foo&...

One can iterate over a list using ~{ and ~} directives. CL-USER> (format t "~{~a, ~}~%" '(1 2 3 4 5)) 1, 2, 3, 4, 5, ~^ can be used to escape if there are no more elements left. CL-USER> (format t "~{~a~^, ~}~%" '(1 2 3 4 5)) 1, 2, 3, 4, 5 A numeric argument can ...

You can make an UILabel with a dynamic height using auto layout. You need to set the numberOfLines to zero (0), and add a minimal height by setting up a constraints with a relation of type .GreaterThanOrEqual on the .Height attribute iOS 6 Swift label.numberOfLines = 0 let heightConstraint = ...

Assumptions: An Oracle JDK has been installed. The JDK was installed to the default directory. Setup steps Open Windows Explorer. In the navigation pane on the left right click on This PC (or Computer for older Windows versions). There is a shorter way without using the explorer in...

Array iteration comes in two flavors, foreach and the classic for-loop: a=(1 2 3 4) # foreach loop for y in "${a[@]}"; do # act on $y echo "$y" done # classic for-loop for ((idx=0; idx < ${#a[@]}; ++idx)); do # act on ${a[$idx]} echo "${a[$idx]}&...

Ruby extends the standard group syntax (...) with a named group, (?<name>...). This allows for extraction by name instead of having to count how many groups you have. name_reg = /h(i|ello), my name is (?<name>.*)/i #i means case insensitive name_input = "Hi, my name is Zaphod Be...

Common mobile-optimized sites use the <meta name="viewport"> tag like this: <meta name="viewport" content="width=device-width, initial-scale=1"> The viewport element gives the browser instructions on how to control the page's dimensions and scaling based...

Assembly language is a human readable form of machine language or machine code which is the actual sequence of bits and bytes on which the processor logic operates. It is generally easier for humans to read and program in mnemonics than binary, octal or hex, so humans typically write code in assemb...

Syntax {condition-to-evaluate} ? {statement-executed-on-true} : {statement-executed-on-false} As shown in the syntax, the Conditional Operator (also known as the Ternary Operator1) uses the ? (question mark) and : (colon) characters to enable a conditional expression of two possible outcomes. It c...

To make express web application modular use router factories: Module: // greet.js const express = require('express'); module.exports = function(options = {}) { // Router factory const router = express.Router(); router.get('/greet', (req, res, next) => { res.end(options....

After receiving the arguments, you can print them as follows: int main(int argc, char **argv) { for (int i = 1; i < argc; i++) { printf("Argument %d: [%s]\n", i, argv[i]); } } Notes The argv parameter can be also defined as char *argv[]. argv[0] may co...

Selenium Grid Node configuration resides on the Node itself and holds the information about network configuration and Node capabilities. The configuration can be applied in various ways: Default Configuration JSON Configuration Command line Configuration JSON Configuration The node configur...

Good for quick notifications that don't require interaction. Swift let alert = UIAlertController(title: "Toast", message: "Hello World", preferredStyle: .Alert) presentViewController(alert, animated: true) { let delay_s:Double = 2 let delayTime = dispatch_time(DI...

The data.table package introduces the function fread. While it is similar to read.table, fread is usually faster and more flexible, guessing the file's delimiter automatically. # get the file path of a CSV included in R's utils package csv_path <- system.file("misc", "exDIF.csv&q...

There are several R packages to read excel files, each of which using different languages or resources, as summarized in the following table: R packageUsesxlsxJavaXLconnectJavaopenxlsxC++readxlC++RODBCODBCgdataPerl For the packages that use Java or ODBC it is important to know details about your s...

This is a slightly more advanced example that shows a few more features of common lisp. We start with a simple Hello, World! function and demonstrate some interactive development at the REPL. Note that any text from a semicolon, ;, to the rest of the line is a comment. CL-USER> (defun hello () ...