Tutorial by Examples: o

The standard (section 23.3.7) specifies that a specialization of vector<bool> is provided, which optimizes space by packing the bool values, so that each takes up only one bit. Since bits aren't addressable in C++, this means that several requirements on vector are not placed on vector<bool...

When the following is compiled, it will return a different value depending on which directives are defined. // Compile with /d:A or /d:B to see the difference string SomeFunction() { #if A return "A"; #elif B return "B"; #else return "C"; #endif ...

Compiler warnings can be generated using the #warning directive, and errors can likewise be generated using the #error directive. #if SOME_SYMBOL #error This is a compiler Error. #elif SOME_OTHER_SYMBOL #warning This is a compiler Warning. #endif

A compiler symbol is a keyword that is defined at compile-time that can be checked for to conditionally execute specific sections of code. There are three ways to define a compiler symbol. They can be defined via code: #define MYSYMBOL They can be defined in Visual Studio, under Project Propert...

Use #region and #endregion to define a collapsible code region. #region Event Handlers public void Button_Click(object s, EventArgs e) { // ... } public void DropDown_SelectedIndexChanged(object s, EventArgs e) { // ... } #endregion These directives are only beneficial whe...

Line #line controls the line number and filename reported by the compiler when outputting warnings and errors. void Test() { #line 42 "Answer" #line filename "SomeFile.cs" int life; // compiler warning CS0168 in "SomeFile.cs" at Line 42 #line defa...

Sometimes you may have a form and want to submit it using ajax. Suppose you have this simple form - <form id="ajax_form" action="form_action.php"> <label for="name">Name :</label> <input name="name" id="name" type="t...

package main import ( "log" "net/http" ) func main() { // Create a mux for routing incoming requests m := http.NewServeMux() // All URLs will be handled by this function m.HandleFunc("/", func(w http.ResponseWriter, r *http.Reque...

#import <Foundation/Foundation.h> @interface Car:NSObject { NSString *CarMotorCode; NSString *CarChassisCode; } - (instancetype)initWithMotorValue:(NSString *) motorCode andChassisValue:(NSInteger)chassisCode; - (void) startCar; - (void) stopCar; @end @implementation Car...

C11 Reading an object will cause undefined behavior, if the object is1: uninitialized defined with automatic storage duration it's address is never taken The variable a in the below example satisfies all those conditions: void Function( void ) { int a; int b = a; } 1 (Quo...

Array types inherit their equals() (and hashCode()) implementations from java.lang.Object, so equals() will only return true when comparing against the exact same array object. To compare arrays for equality based on their values, use java.util.Arrays.equals, which is overloaded for all array types...

// Create an array with a fixed size and type. var array = new Uint8Array(5); // Generate cryptographically random values crypto.getRandomValues(array); // Print the array to the console console.log(array); crypto.getRandomValues(array) can be used with instances of the following classes...

Setting values Using Unicode directly var str: String = "I want to visit 北京, Москва, मुंबई, القاهرة, and 서울시. 😊" var character: Character = "🌍" Using hexadecimal values var str: String = "\u{61}\u{5927}\u{1F34E}\u{3C0}" // a大🍎π var character: Character = &quo...

6 var myIterableObject = {}; // An Iterable object must define a method located at the Symbol.iterator key: myIterableObject[Symbol.iterator] = function () { // The iterator should return an Iterator object return { // The Iterator object must implement a method, next() next: func...

using System; using System.Dynamic; dynamic info = new ExpandoObject(); info.Id = 123; info.Another = 456; Console.WriteLine(info.Another); // 456 Console.WriteLine(info.DoesntExist); // Throws RuntimeBinderException

You can use a colon and the standard numeric format syntax to control how numbers are formatted. var decimalValue = 120.5; var asCurrency = $"It costs {decimalValue:C}"; // String value is "It costs $120.50" (depending on your local currency settings) var withThreeDecimal...

Expressions in C++ are assigned a particular value category, based on the result of those expressions. Value categories for expressions can affect C++ function overload resolution. Value categories determines two important-but-separate properties about an expression. One property is whether the exp...

Background TypeScript is a typed superset of JavaScript that compiles directly to JavaScript code. TypeScript files commonly use the .ts extension. Many IDEs support TypeScript without any other setup required, but TypeScript can also be compiled with the TypeScript Node.JS package from the command...

In this example, we illustrate string manipulation in MATLAB MEX. We will create a MEX-function that accepts a string as input from MATLAB, copy the data into C-string, modify it and convert it back to mxArray returned to the MATLAB side. The main objective of this example is to show how strings ca...

Since anonymous types are not named, variables of those types must be implicitly typed (var). var anon = new { Foo = 1, Bar = 2 }; // anon.Foo == 1 // anon.Bar == 2 If the member names are not specified, they are set to the name of the property/variable used to initialize the object. int foo ...