Tutorial by Examples: for

Some API calls can succeed or fail in more than one way. The APIs commonly return additional information for both successful invocations as well as errors (e.g. CreateMutex). if ( CreateMutexW( NULL, TRUE, L"Global\\MyNamedMutex" ) == NULL ) { // Failure: get additional information. ...

You can write the default protocol implementation for a specific class. protocol MyProtocol { func doSomething() } extension MyProtocol where Self: UIViewController { func doSomething() { print("UIViewController default protocol implementation") } } class M...

In many other languages, if you run the following (Java example) if("asgdsrf" == 0) { //do stuff } ... you'll get an error. You can't just go comparing strings to integers like that. In Python, this is a perfectly legal statement - it'll just resolve to False. A common gotcha ...

When you are copying a string into a malloced buffer, always remember to add 1 to strlen. char *dest = malloc(strlen(src)); /* WRONG */ char *dest = malloc(strlen(src) + 1); /* RIGHT */ strcpy(dest, src); This is because strlen does not include the trailing \0 in the length. If you take the ...

A programming best practice is to free any memory that has been allocated directly by your own code, or implicitly by calling an internal or external function, such as a library API like strdup(). Failing to free memory can introduce a memory leak, which could accumulate into a substantial amount of...

If realloc fails, it returns NULL. If you assign the value of the original buffer to realloc's return value, and if it returns NULL, then the original buffer (the old pointer) is lost, resulting in a memory leak. The solution is to copy into a temporary pointer, and if that temporary is not NULL, th...

Stanford CoreNLP is a popular Natural Language Processing toolkit supporting many core NLP tasks. To download and install the program, either download a release package and include the necessary *.jar files in your classpath, or add the dependency off of Maven central. See the download page for mor...

First, references will be added to the CLR assemblies that will be used. import clr clr.AddReference('System.Windows.Forms') Next the names we will use are imported. from System.Windows.Forms import Application, Form A class will be created for the Hello World form using Form as its subclas...

Below won't work on a Windows machine $file = $request->file('file_upload'); $sampleName = 'UserUpload'; $destination = app_path() . '/myStorage/'; $fileName = $sampleName . '-' . date('Y-m-d-H:i:s') . '.' . $file->getClientOriginalExtension(); $file->move($destination, $fileName); ...

add 'django.contrib.postgres' to your INSTALLED_APPS install psycopg2

Since PHP7, it is possible to bind a closure just for one call, thanks to the call method. For instance: <?php class MyClass { private $property; public function __construct($propertyValue) { $this->property = $propertyValue; } } $myClosure = function() ...

Tips & Tricks to avoid nasty situations EC2 Instances and EBS Set IAM Roles. Unlike tags, the IAM Role is set once and for all on EC2 instanciation (even after 4 years) ! Try to identify and categorize beforehand your instances so you can give an them appropriate IAM roles. IAM Roles are ...

Placeholders in the query string need to be set by using the set* methods: String sql = "SELECT * FROM EMP WHERE JOB = ? AND SAL > ?"; //Create statement to make your operations PreparedStatement statement = connection.prepareStatement(sql); statement.setString(1, "MANAGER&...

A simple example defining a Function that gets triggered by a Queue message: public static void StringMessage([QueueTrigger("my_queue")] string plainText) { //... } It also supports POCO serialization: public static void POCOMessage([QueueTrigger("my_queue")] MyPO...

A simple example of a Function that gets triggered when a Azure Storage Blob is modified: public static async Task BlobTrigger( [BlobTrigger("my_container/{name}.{ext}")] Stream input, string name, string ext) { //Blob with name {name} and extension {ext} using (StreamRead...

<form asp-action="create" asp-controller="Home"> <!--Your form elements goes here--> </form>

<form asp-action="create" asp-controller="Home" asp-route-returnurl="dashboard" asp-route-from="google"> <!--Your form elements goes here--> </form> This will generate the below markup <form action=&qu...

Catalog.objects.filter(titles__Pro_Git='Scott Chacon and Ben Straub')

The @for directive allows you to loop through some code for a set amount of iterations and has two forms: @for <var> from <start> through <end> {} @for <var> from <start> to <end> {} The difference in the two forms is the through and the to; the through key...

Here is a program that calls malloc but not free: #include <stdio.h> #include <stdlib.h> int main(int argc, char **argv) { char *s; s = malloc(26); // the culprint return 0; } With no extra arguments, valgrind will not look for this error. But if we turn on...