Tutorial by Examples: ed

By adding a header with content type as JSON: <?php $result = array('menu1' => 'home', 'menu2' => 'code php', 'menu3' => 'about'); //return the json response : header('Content-Type: application/json'); // <-- header declaration echo json_encode($result, true); // <--- e...

Caffe has a build-in input layer tailored for image classification tasks (i.e., single integer label per input image). This input "Data" layer is built upon an lmdb or leveldb data structure. In order to use "Data" layer one has to construct the data structure with all training d...

What: Caching can optimize computation in Spark. Caching stores data in memory and is a special case of persistence. Here is explained what happens when you cache an RDD in Spark. Why: Basically, caching saves an interim partial result - usually after transformations - of your original data. So, ...

From dataframe: mtrdd <- createDataFrame(sqlContext, mtcars) From csv: For csv's, you need to add the csv package to the environment before initiating the Spark context: Sys.setenv('SPARKR_SUBMIT_ARGS'='"--packages" "com.databricks:spark-csv_2.10:1.4.0" "sparkr-shel...

SQL Server 2008 R2 SET TRANSACTION ISOLATION LEVEL READ COMMITTED This isolation level is the 2nd most permissive. It prevents dirty reads. The behavior of READ COMMITTED depends on the setting of the READ_COMMITTED_SNAPSHOT: If set to OFF (the default setting) the transaction uses shared l...

If you're using an icon to add some extra decoration or branding, it does not need to be announced to users as they are navigating your site or app aurally. Additionally, if you're using an icon to visually re-emphasize or add styling to content already present in your HTML, it does not need to be r...

When writing wrappers for unmanaged resources, you should subclass SafeHandle rather than trying to implement IDisposable and a finalizer yourself. Your SafeHandle subclass should be as small and simple as possible to minimize the chance of a handle leak. This likely means that your SafeHandle imple...

Visual Studio Team Services is an hosted version of Microsoft Team Foundation Server. It doesn't require any installation as it's already done by Microsoft itself. In order to start using Visual Studio Team Services you need to create an account here by pressing the Free account button. It will red...

The [[maybe_unused]] attribute is created for indicating in code that certain logic might not be used. This if often linked to preprocessor conditions where this might be used or might not be used. As compilers can give warnings on unused variables, this is a way of suppressing them by indicating in...

The predicate function matches can be used to evaluate strings on the fly without use of any object declarations. IF matches( val = 'Not a hex string' regex = '[0-9a-f]*' ). cl_demo_output=>display( 'This will not display' ). ELSEIF matches( val = '6c6f7665' reg...

As already pointed out in other pitfalls, catching all exceptions by using try { // Some code } catch (Exception) { // Some error handling } Comes with a lot of different problems. But one perticular problem is that it can lead to deadlocks as it breaks the interrupt system when writ...

The Symbol.for method allows you to register and look up global symbols by name. The first time it is called with a given key, it creates a new symbol and adds it to the registry. let a = Symbol.for('A'); The next time you call Symbol.for('A'), the same symbol will be returned instead of a new o...

The std::nth_element algorithm takes three iterators: an iterator to the beginning, nth position, and end. Once the function returns, the nth element (by order) will be the nth smallest element. (The function has more elaborate overloads, e.g., some taking comparison functors; see the above link for...

When static_cast is used to convert T D::* to T B::*, the member pointed to must belong to a class that is a base class or derived class of B. Otherwise the behavior is undefined. See Derived to base conversion for pointers to members

In this example, a destructor is explicitly invoked for an object that will later be automatically destroyed. struct S { ~S() { std::cout << "destroying S\n"; } }; int main() { S s; s.~S(); } // UB: s destroyed a second time here A similar issue occurs when a st...

To change a text file is not easy because its content must be moved around. For small files easiest method is to read its content in memory and then write back modified text. In this example we read all lines from a file and drop all blank lines then we write back to original path: File.WriteAllLi...

This snippet is an helper function to enumerate all files older than a specified age, it's useful - for example - when you have to delete old log files or old cached data. static IEnumerable<string> EnumerateAllFilesOlderThan( TimeSpan maximumAge, ...

echo off cls sqlcmd.exe -S "your server name" -U "sql user name" -P "sql password" -d "name of databse" -Q "here you may write your query/stored procedure" Batch files like these can be used to automate tasks, for example to make backups of ...

The canonical way of writing code inside documentation is with the {@code } construct. If you have multiline code wrap inside <pre></pre>. /** * The Class TestUtils. * <p> * This is an {@code inline("code example")}. * <p> * You should wrap it in pre tags...

This command has several related yet distinct forms. del v If v is a variable, the command del v removes the variable from its scope. For example: x = 5 print(x) # out: 5 del x print(x) # NameError: name 'f' is not defined Note that del is a binding occurence, which means that unless expl...