Tutorial by Examples: re

'Declare and assign a 1-character fixed-width string Dim middleInitial As String * 1 'middleInitial must be 1 character in length middleInitial = "M" 'Declare and assign a 2-character fixed-width string `stateCode`, 'must be 2 characters in length Dim stateCode As String * 2 stateC...

'Declare, dimension and assign a string array with 3 elements Dim departments(2) As String departments(0) = "Engineering" departments(1) = "Finance" departments(2) = "Marketing" 'Declare an undimensioned string array and then dynamically assign with 'the results...

div { direction: ltr; /* Default, text read read from left-to-right */ } .ex { direction: rtl; /* text read from right-to-left */ } .horizontal-tb { writing-mode: horizontal-tb; /* Default, text read from left-to-right and top-to-bottom. */ } .vertical-rtl { writing-mode: v...

This is an example of using Android Support Library V7 RecyclerView. Support libraries are generally recommended because they provide backward-compatible versions of new features, provide useful UI elements that are not included in the framework, and provide a range of utilities that apps can draw o...

To remove a variable from memory, one can use the Remove-Item cmdlet. Note: The variable name does NOT include the $. Remove-Item Variable:\foo Variable has a provider to allow most *-item cmdlets to work much like file systems. Another method to remove variable is to use Remove-Variable cmdlet...

Please read Preventing SQL injection with Parametrized Queries for a complete discussion of why prepared statements help you secure your SQL statements from SQL Injection attacks The $conn variable here is a MySQLi object. See MySQLi connect example for more details. For both examples, we assume t...

How do you go about using an instance of a (possibly further) inherited generic type within a method declaration in the generic type itself being declared? This is one of the problems you will face when you dig a bit deeper into generics, but still a fairly common one. Assume we have a DataSeries&l...

DataObjects in SilverStripe represent a database table row. The fields in the model have magic methods that handle getting and setting data via their property names. Given we have a simple DataObject as an example: class Fruit extends DataObject { private static $db = ['Name' => 'Varchar'...

Most streams must be closed when you are done with them, otherwise you could introduce a memory leak or leave a file open. It is important that streams are closed even if an exception is thrown. Java SE 7 try(FileWriter fw = new FileWriter("outfilename"); BufferedWriter bw = new Buf...

As a root user: nginx -s restart Ubuntu example sudo service nginx restart

As a root user: sudo nginx -s reload Ubuntu 14.04 example sudo service nginx reload Ubuntu 16.04 example sudo systemctl reload nginx Before reloading, it is a good idea to check config for syntax errors: sudo nginx -t Or sudo service nginx configtest

This is the first phase of referencing. Essentially when you assign by reference, you're allowing two variables to share the same value as such. $foo = &$bar; $foo and $bar are equal here. They do not point to one another. They point to the same place (the "value"). You can also...

Occasionally there comes time for you to implicitly return-by-reference. Returning by reference is useful when you want to use a function to find to which variable a reference should be bound. Do not use return-by-reference to increase performance. The engine will automatically optimize this o...

This allows you to pass a variable by reference to a function or element that allows you to modify the original variable. Passing-by-reference is not limited to variables only, the following can also be passed by reference: New statements, e.g. foo(new SomeClass) References returned from functi...

The following example encrypts a given data block using AES. The encryption key is derived in a secure way (random salt, 1000 rounds of SHA-256). The encryption uses AES in CBC mode with random IV. Note that the data stored in the class EncryptedData (salt, iv, and encryptedData) can be concatenate...

add filter method in RecyclerView.Adapter: public void filter(String text) { if(text.isEmpty()){ items.clear(); items.addAll(itemsCopy); } else{ ArrayList<PhoneBookItem> result = new ArrayList<>(); text = text.toLower...

We can provision remote systems with Ansible. You should have an SSH key-pair and you should take your SSH public key to the machine ~/.ssh/authorized_keys file. The porpuse is you can login without any authorization. Prerequisites: Ansible You need an Inventory file (for ex.: development.ini...

CSRF is an attack which forces end user to execute unwanted actions on a web application in which he/she is currently authenticated. It can happen because cookies are sent with every request to a website - even when those requests come from a different site. We can use csurf module for creating cs...

While redux itself is entirely synchronous, you can use a middleware such as redux-thunk to handle asynchronous actions. A "thunk" is another name for a callback. It is a function that is usually passed as an argument to be called at a later time. To use, apply the middleware to you...

Patterns can be specified as regular expressions: /regular expression/ {action} For example: echo "[email protected] not an email" | awk '/[^@]+@.+/ {print}' Produces: [email protected] Note that an action consisting only of the print statement can be omitted entirely. The abo...