Tutorial by Examples: ce

/** * Checks if a resource exists by sending a HEAD-Request. * @param url The url of a resource which has to be checked. * @return true if the response code is 200 OK. */ public static final boolean checkIfResourceExists(URL url) throws IOException { HttpURLConnection conn = (HttpURLCo...

ACCEPT variable. ACCEPT variable FROM CONSOLE. ACCEPT variable FROM ENVIRONMENT "path". ACCEPT variable FROM COMMAND-LINE. ACCEPT variable FROM ARGUMENT-NUMBER ACCEPT variable FROM ARGUMENT-VALUE ACCEPT variable AT 0101. ACCEPT screen-variable. ACCEPT today FROM DATE. ACCE...

In C#, an array name and a pointer to a data type same as the array data, are not the same variable type. For example, int *p and int[] p, are not same type. You can increment the pointer variable p because it is not fixed in memory but an array address is fixed in memory, and you can't increment th...

app.ts import {Component} from '@angular/core'; import {Platform, ionicBootstrap} from 'ionic-angular'; import {StatusBar} from 'ionic-native'; import {LoginPage} from './pages/login/login'; import {FIREBASE_PROVIDERS, defaultFirebase, AuthMethods, AuthProviders, firebaseAuthConfig} from 'angul...

MERGE INTO targetTable t USING sourceTable s ON t.PKID = s.PKID WHEN MATCHED AND NOT EXISTS ( SELECT s.ColumnA, s.ColumnB, s.ColumnC INTERSECT SELECT t.ColumnA, t.ColumnB, s.ColumnC ) THEN UPDATE SET t.Colum...

This example demonstrates how pointers can be used for C-like access to C# arrays. unsafe { var buffer = new int[1024]; fixed (int* p = &buffer[0]) { for (var i = 0; i < buffer.Length; i++) { *(p + i) = i; } } } The unsafe keyw...

C# inherits from C and C++ the usage of the symbol -> as a means of accessing the members of an instance through a typed pointer. Consider the following struct: struct Vector2 { public int X; public int Y; } This is an example of the usage of -> to access its members: Vector2...

In .NET, the GC allocates objects when there are no references left to them. Therefore, while an object can still be reached from code (there is a strong reference to it), the GC will not allocate this object. This can become a problem if there are a lot of large objects. A weak reference is a ref...

In most object oriented languages, allocating memory for an object and initializing it is an atomic operation: // Both allocates memory and calls the constructor MyClass object = new MyClass(); In Objective-C, these are separate operations. The class methods alloc (and its historic sibling allo...

context.globalCompositeOperation = "source-in"; source-in compositing clips new drawings inside an existing shape. Note: Any part of the new drawing that falls outside the existing drawing is erased. context.drawImage(oval,0,0); context.globalCompositeOperation='source-in'; // pictu...

It's important to handle exceptions in your service. When developing the service, you can set the WCF to provide more detailed information, adding this tag to configuration file, usually Web.config: <serviceDebug includeExceptionDetailInFaults="true"/> This tag must be placed w...

You can handle exceptions and throw a most friendly message like 'Unavailable service' throwing a FaultException: try { // your service logic here } catch (Exception ex) { // You can do something here, like log the original exception throw new FaultException("There was a pro...

The FaultException can also includes a FaultCode, that is a string data you can use to pass additional information, so the client can be able to distinguish different exceptions: try { // your service logic here } catch (Exception ex) { throw new FaultException("There was a proble...

Sometimes, one wants to run some initialization code once before testing a condition. In certain other languages, this kind of loop has special do-while syntax. However, this syntax can be replaced with a regular while loop and break statement, so Julia does not have specialized do-while syntax. Ins...

context.globalCompositeOperation = 'source-atop' source-atop compositing clips new image inside an existing shape. // gold filled rect ctx.fillStyle='gold'; ctx.fillRect(100,100,100,75); // shadow ctx.shadowColor='black'; ctx.shadowBlur=10; // restrict new draw to cover existing pixels ct...

Render a white rectangle over an image with the composite operation ctx.globalCompositeOperation = 'difference'; The amount of the effect can be controled with the alpha setting // Render the image ctx.globalCompositeOperation='source-atop'; ctx.drawImage(image, 0, 0); // set the composite...

Map k v provides a Monoid instance with the following semantics: mempty is the empty Map, i.e. the same as Map.empty m1 <> m2 is the left-biased union of m1 and m2, i.e. if any key is present both in m1 and m2, then the value from m1 is picked for m1 <> m2. This operation is also ava...

This a python example function for sequence writing in fasta format. Parameters: filename(String) - A file name for writing sequence in fasta format. seq(String) - A DNA or RNA sequence. id(String) - The ID of the given sequence. desc(String) - A short description of the given sequence. im...

You can customize your Layout of Views by click-dragging the Tab of any View to one of several locations. Dropping a Tab in the Tab Area of an existing window will add the Tab beside any existing Tabs. Alternatively, dropping a Tab in any Dock Zone will add the View in a new window. Tabs can also...

Using a pipe makes the output of a command be the input of the next one. ls -1 | grep -c ".conf" In this case the ouput of the ls command is used as the input of the grep command. The result will be the number of files that include ".conf" in their name. This can be used to ...