Tutorial by Examples: ch

Overload resolution occurs after name lookup. This means that a better-matching function will not be selected by overload resolution if it loses name lookup: void f(int x); struct S { void f(double x); void g() { f(42); } // calls S::f because global f is not visible here, ...

Visual Basic has Left, Right, and Mid functions that returns characters from the Left, Right, and Middle of a string. These methods does not exist in C#, but can be implemented with Substring(). They can be implemented as an extension methods like the following: public static class StringExtens...

$ react-native -v Example Output react-native-cli: 0.2.0 react-native: n/a - not inside a React Native project directory //Output from different folder react-native: react-native: 0.30.0 // Output from the react native project directory

You can also pattern match on Elixir Data Structures such as Lists. Lists Matching on a list is quite simple. [head | tail] = [1,2,3,4,5] # head == 1 # tail == [2,3,4,5] This works by matching the first (or more) elements in the list to the left hand side of the | (pipe) and the rest of the ...

CountDownLatch A synchronization aid that allows one or more threads to wait until a set of operations being performed in other threads completes. A CountDownLatch is initialized with a given count. The await methods block until the current count reaches zero due to invocations of the count...

string nullString = null; string emptyString = ""; string whitespaceString = " "; string tabString = "\t"; string newlineString = "\n"; string nonEmptyString = "abc123"; bool result; result = String.IsNullOrEmpty(nullString); ...

$this->helper('checkout/url')->getCheckoutUrl(); OR Mage::helper('checkout/url')->getCheckoutUrl();

In attempt to send a response asynchronously from chrome.runtime.onMessage callback we might try this wrong code: chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) { $.ajax({ url: 'https://www.google.com', method: 'GET', success: functio...

Suppose we need to do the sum of each column in a dataset set.seed(20) df1 <- data.frame(ID = rep(c("A", "B", "C"), each = 3), V1 = rnorm(9), V2 = rnorm(9)) m1 <- as.matrix(df1[-1]) There are many ways to do this. Using base R, the best option would be col...

Suppose you have this type: data Person = Person { name :: String, age:: Int } deriving (Show, Eq) and two values: alex = Person { name = "Alex", age = 21 } jenny = Person { name = "Jenny", age = 36 } a new value of type Person can be created by copying from alex, specif...

The foreach statement is used to loop through arrays. For each iteration the value of the current array element is assigned to $value variable and the array pointer is moved by one and in the next iteration next element will be processed. The following example displays the items in the array a...

Using the Vector.<T> type and the for each loop is more performant than a conventional array and for loop: Good: var list:Vector.<Sprite> = new <Sprite>[]; for each(var sprite:Sprite in list) { sprite.x += 1; } Bad: var list:Array = []; for (var i:int = 0; i < ...

If you need to count distinct characters then, for the reasons explained in Remarks section, you can't simply use Length property because it's the length of the array of System.Char which are not characters but code-units (not Unicode code-points nor graphemes). If, for example, you simply write tex...

If you need to count characters then, for the reasons explained in Remarks section, you can't simply use Length property because it's the length of the array of System.Char which are not characters but code-units (not Unicode code-points nor graphemes). Correct code is then: int length = text.Enume...

Because of the reasons explained in Remarks section you can't simply do this (unless you want to count occurrences of a specific code-unit): int count = text.Count(x => x == ch); You need a more complex function: public static int CountOccurrencesOf(this string text, string character) { ...

The below examples use the new form API introduced in RC3. pw-change.template.html <form class="container" [formGroup]="pwChangeForm"> <label for="current">Current Password</label> <input id="current" formControlName="curr...

In Java, there is a built-in language-level locking mechanism: the synchronized block, which can use any Java object as an intrinsic lock (i.e. every Java object may have a monitor associated with it). Intrinsic locks provide atomicity to groups of statements. To understand what that means for us, ...

import pandas as pd chunksize = [n] for chunk in pd.read_csv(filename, chunksize=chunksize): process(chunk) delete(chunk)

INotifyPropertyChanged is an interface used by binding sources (i.e. the DataContext) to let the user interface or other components know that a property has been changed. WPF automatically updates the UI for you when it sees the PropertyChanged event raised. It is desirable to have this interface im...

name:"john doe"~1 Searches for multiple terms within a specific term distance (~1), i.e will find text containing john anonymous doe but not john second name doe