Tutorial by Examples: en

The year, month or day components of a DATE data type can be found using the EXTRACT( [ YEAR | MONTH | DAY ] FROM datevalue ) SELECT EXTRACT (YEAR FROM DATE '2016-07-25') AS YEAR, EXTRACT (MONTH FROM DATE '2016-07-25') AS MONTH, EXTRACT (DAY FROM DATE '2016-07-25') AS DAY FROM D...

In some cases you might want to add an additional description to an enum value, for instance when the enum value itself is less readable than what you might want to display to the user. In such cases you can use the System.ComponentModel.DescriptionAttribute class. For example: public enum Possibl...

$sce ("Strict Contextual Escaping") is a built-in angular service that automatically sanitize content and internal sources in templates. injecting external sources and raw HTML into the template requires manual wrapping of$sce. In this example we'll create a simple $sce sanitation f...

Concatenating strings using a StringBuilder can offer performance advantages over simple string concatenation using +. This is due to the way memory is allocated. Strings are reallocated with each concatenation, StringBuilders allocate memory in blocks only reallocating when the current block is e...

The String.Join method can be used to concatenate multiple elements from a string array. string[] value = {"apple", "orange", "grape", "pear"}; string separator = ", "; string result = String.Join(separator, value, 1, 2); Console.WriteLine(resu...

The "listener" or "observer" pattern is the most common strategy for creating asynchronous callbacks in Android development. public class MyCustomObject { //1 - Define the interface public interface MyCustomObjectListener { public void onAction(String ac...

Rebasing when pulling If you are pulling in fresh commits from the remote repository and you have local changes on the current branch then git will automatically merge the remote version and your version. If you would like to reduce the number of merges on your branch you can tell git to rebase you...

There are a few changes where instant won't do its trick and a full build and reinstall fo your app will happen just like it used to happen before Instant Run was born. Change the app manifest Change resources referenced by the app manifest Change an Android widget UI element (requires a Clean ...

On of the overloads of the Select extension methods also passes the index of the current item in the collection being selected. These are a few uses of it. Get the "row number" of the items var rowNumbers = collection.OrderBy(item => item.Property1) .ThenBy...

DataTables has the capability to enable or disable a number of its features, such as paging or searching. To choose these options, simply select them in your initialization: $(document).ready(function() { $('#tableid').DataTable( { "paging": false, //Turn off paging, all r...

Random UUID Swift func randomUUID() -> NSString{ return NSUUID.UUID().UUIDString() } Objective-C + (NSString *)randomUUID { if(NSClassFromString(@"NSUUID")) { // only available in iOS >= 6.0 return [[NSUUID UUID] UUIDString]; } CFUUIDRef uuidRef = ...

Let's say you have two commits d9e1db9 and 5651067 and want to see what happened between them. d9e1db9 is the oldest ancestor and 5651067 is the final descendant in the chain of commits. gitk --ancestry-path d9e1db9 5651067

Swift: if let url = URL(string: "mailto://[email protected]") { if UIApplication.shared.canOpenURL(url) { UIApplication.shared.openURL(url) } else { print("Cannot open URL") } } Objective-C: NSURL *url = [NSURL URLWithString:@"mailto://az...

Whitespace matters when assigning variables. foo = 'bar' # incorrect foo= 'bar' # incorrect foo='bar' # correct The first two will result in syntax errors (or worse, executing an incorrect command). The last example will correctly set the variable $foo to the text "bar".

To execute a script file with the bash executable found in the PATH environment variable by using the executable env, the first line of a script file must indicate the absolute path to the env executable with the argument bash: #!/usr/bin/env bash The env path in the shebang is resolved and used...

Event delegation is a process which allow us to avoid adding event listeners to specific nodes; instead, the event listener is added to parent node. This mechanism utilizes the event propagation/bubbling to handle an event at a higher level element/node in the DOM instead of using the element on whi...

<svg width="800px" height="600px"> <defs> <filter id="greyscale"> <feColorMatrix type="matrix" values="0 1 0 0 0 0 1 0 0 0 0 1 0 0 0 ...

To produce nested JSON object, you need to simply add one JSON object to another: JSONObject mainObject = new JSONObject(); // Host object JSONObject requestObject = new JSONObject(); // Included object try { requestObject.put("lastname", lastname); reques...

A common problem when working with Unity is when 2 or more developers are modifying a Unity scene or prefab (*.unity files). Git does not know how to merge them correctly out of the box. Thankfully the Unity team deployed a tool called SmartMerge which makes simple merge automatic. The first thing...

As a root user run: nginx -s reopen