Tutorial by Examples: co

<?php namespace models; use yii\db\ActiveRecord; use yii\behaviors\TimestampBehavior; class Post extends ActiveRecord { public static function tableName() { return 'post'; } public function rules() { ...

Generators can be used to implement coroutines: # create and advance generator to the first yield def coroutine(func): def start(*args,**kwargs): cr = func(*args,**kwargs) next(cr) return cr return start # example coroutine @coroutine def adder(sum = 0): ...

To get your most recent stash after running git stash, use git stash apply To see a list of your stashes, use git stash list You will get a list that looks something like this stash@{0}: WIP on master: 67a4e01 Merge tests into develop stash@{1}: WIP on master: 70f0d95 Add user role to lo...

async functions do not replace the Promise type; they add language keywords that make promises easier to call. They are interchangeable: async function doAsyncThing() { ... } function doPromiseThing(input) { return new Promise((r, x) => ...); } // Call with promise syntax doAsyncThing() ...

The Oracle SQL and PL/SQL || operator allows you to concatenate 2 or more strings together. Example: Assuming the following customers table: id firstname lastname --- ----------- ---------- 1 Thomas Woody Query: SELECT firstname || ' ' || lastname || ' is in my database.' a...

If value types are assigned to variables of type object they are boxed - the value is stored in an instance of a System.Object. This can lead to unintended consequences when comparing values with ==, e.g.: object left = (int)1; // int in an object box object right = (int)1; // int in an object bo...

Boxed value types can only be unboxed into their original Type, even if a conversion of the two Types is valid, e.g.: object boxedInt = (int)1; // int boxed in an object long unboxedInt1 = (long)boxedInt; // invalid cast This can be avoided by first unboxing into the original Type, e.g.: lon...

The fetch function does not send cookies by default. There are two possible ways to send cookies: Only send cookies if the URL is on the same origin as the calling script. fetch('/login', { credentials: 'same-origin' }) Always send cookies, even for cross-origin calls. fetch('htt...

function foo() { console.trace('My log statement'); } foo(); Will display this in the console: My log statement VM696:1 foo @ VM696:1 (anonymous function) @ (program):1 Note: Where available it's also useful to know that the same stack trace is accessible a...

ALTER TABLE Employees ALTER COLUMN StartingDate DATETIME NOT NULL DEFAULT (GETDATE()) This query will alter the column datatype of StartingDate and change it from simple date to datetime and set default to current date.

The editor.apply() method is asynchronous, while editor.commit() is synchronous. Obviously, you should call either apply() or commit(). 2.3 SharedPreferences settings = getSharedPreferences(PREFS_FILE, MODE_PRIVATE); SharedPreferences.Editor editor = settings.edit(); editor.putBoolean(PREF_CONS...

In Python 2, an octal literal could be defined as >>> 0755 # only Python 2 To ensure cross-compatibility, use 0o755 # both Python 2 and Python 3

Swift import SystemConfiguration /// Class helps to code reuse in handling internet network connections. class NetworkHelper { /** Verify if the device is connected to internet network. - returns: true if is connected to any internet network, false if is not co...

\bfoo\b will match the complete word with no alphanumeric and _ preceding or following by it. Taking from regularexpression.info There are three different positions that qualify as word boundaries: Before the first character in the string, if the first character is a word character. After...

Define a new type Person using namedtuple like this: Person = namedtuple('Person', ['age', 'height', 'name']) The second argument is the list of attributes that the tuple will have. You can list these attributes also as either space or comma separated string: Person = namedtuple('Person', 'age,...

By default, Interface Builder doesn't accept the CGColor datatype, so to allow adding a CGColor using user defined attributes in interface builder; one may want to use an extension like this: Swift Extension : extension CALayer { func borderUIColor() -> UIColor? { return borderCol...

NSSet *set = [NSSet set]; NSArray *array = [NSArray array]; NSArray *fromSet = [set allObjects]; NSSet *fromArray = [NSSet setWithArray:array];

Function DisableShift() 'This function disable the shift at startup. This action causes 'the Autoexec macro and Startup properties to always be executed. On Error GoTo errDisableShift Dim db As DAO.Database Dim prop As DAO.Property Const conPropNotFound = 3270 Set db = C...

Function EnableShift() 'This function enables the SHIFT key at startup. This action causes 'the Autoexec macro and the Startup properties to be bypassed 'if the user holds down the SHIFT key when the user opens the database. On Error GoTo errEnableShift Dim db As DAO.Database Dim p...

Tuples can be compared based on their elements. As an example, an enumerable whose elements are of type Tuple can be sorted based on comparisons operators defined on a specified element: List<Tuple<int, string>> list = new List<Tuple<int, string>>(); list.Add(new Tuple<...