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 $http service is a function which generates an HTTP request and returns a promise.
General Usage
// Simple GET request example:
$http({
method: 'GET',
url: '/someUrl'
}).then(function successCallback(response) {
// this callback will be called asynchronously
// when the respo...
Counting rows based on a specific column value:
SELECT category, COUNT(*) AS item_count
FROM item
GROUP BY category;
Getting average income by department:
SELECT department, AVG(income)
FROM employees
GROUP BY department;
The important thing is to select only columns specified in the GRO...
A value of a struct type can be written using a struct literal that specifies values for its fields.
type Point struct { X, Y int }
p := Point{1, 2}
The above example specifies every field in the right order. Which is not useful, because programmers have to remember the exact fields in order. M...
The "listener" or "observer" pattern is the most common strategy for creating asynchronous callbacks in Android development.
public class MyCustomObject {
//1 - Define the interface
public interface MyCustomObjectListener {
public void onAction(String ac...
Rebasing when pulling
If you are pulling in fresh commits from the remote repository and you have local changes on the current branch then git will automatically merge the remote version and your version. If you would like to reduce the number of merges on your branch you can tell git to rebase you...
var regExp = new RegExp(r"(\w+)");
var str = "Parse my string";
Iterable<Match> matches = regExp.allMatches(str);
It's a good idea to use "raw strings" (prefix with r)
when writing regular expressions so you can use unescaped backslashes in your expression.
...
If you want to keep on-premises copy of the Gradle and let the Wrapper use it in the builds, you can set the distributionUrl pointing to your copy on the wrapper task:
task wrapper(type: Wrapper) {
gradleVersion = '2.0'
distributionUrl = "http\://server/dadada/gradle-${gradleVersion}...
I like to wrap my OkHttp into a class called HttpClient for example, and in this class I have methods for each of the major HTTP verbs, post, get, put and delete, most commonly. (I usually include an interface, in order to keep for it to implement, in order to be able to easily change to a different...
We have a C library named my_random that produces random numbers from a custom distribution. It provides two functions that we want to use: set_seed(long seed) and rand() (and many more we do not need). In order to use them in Cython we need to
define an interface in the .pxd file and
call the f...
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...
TakeWhile returns elements from a sequence as long as the condition is true
int[] list = { 1, 10, 40, 50, 44, 70, 4 };
var result = list.TakeWhile(item => item < 50).ToList();
// result = { 1, 10, 40 }
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...
DataTables comes with an extensive API which is used to manipulate or obtain information about the DataTables on a page.
The API can be accessed in 3 ways:
var table = $('#tableid').DataTable(); //DataTable() returns an API instance immediately
var table = $('#tableid').dataTable().api(); //dataT...
Swing supports quite a few native L&Fs.
You can always easily install one without calling for a specific L&F class:
public class SystemLookAndFeel
{
public static void main ( final String[] args )
{
// L&F installation should be performed within EDT (Event Dispatch ...
public class CustomLookAndFeel
{
public static void main ( final String[] args )
{
// L&F installation should be performed within EDT (Event Dispatch Thread)
// This is important to avoid any UI issues, exceptions or even deadlocks
SwingUtilities.invokeLater...
Lambdas are meant to provide inline implementation code for single method interfaces and the ability to pass them around as we have been doing with normal variables. We call them Functional Interface.
For example, writing a Runnable in anonymous class and starting a Thread looks like:
//Old way
n...
