C_Sharp_Language

C Sharp TutorialC Sharp .NET Compiler Platform (Roslyn)C Sharp 3.0 FeaturesC Sharp 4.0 FeaturesC Sharp 5.0 FeaturesC Sharp 6.0 FeaturesC Sharp 7.0 FeaturesC Sharp Access ModifiersC Sharp Access network shared folder with username and passwordC Sharp Accessing DatabasesC Sharp Action FiltersC Sharp Aliases of built-in typesC Sharp an overview of collectionsC Sharp Anonymous typesC Sharp ArraysC Sharp ASP.NET IdentityC Sharp AssemblyInfo.cs ExamplesC Sharp Async-AwaitC Sharp Async/await, Backgroundworker, Task and Thread ExamplesC Sharp Asynchronous SocketC Sharp AttributesC Sharp Authentication handlerC Sharp BackgroundWorkerC Sharp BigIntegerC Sharp Binary SerializationC Sharp BindingListC Sharp Built-in TypesC Sharp CachingC Sharp CastingC Sharp Checked and UncheckedC Sharp CLSCompliantAttributeC Sharp Code ContractsC Sharp Code Contracts and AssertionsC Sharp Collection InitializersC Sharp Comments and regionsC Sharp Common String OperationsC Sharp Conditional StatementsC Sharp Constructors and FinalizersC Sharp Creating Own MessageBox in Windows Form ApplicationC Sharp Creational Design PatternsC Sharp Cryptography (System.Security.Cryptography)C Sharp Data AnnotationC Sharp DateTime MethodsC Sharp DelegatesC Sharp Dependency InjectionC Sharp DiagnosticsC Sharp Dynamic typeC Sharp EnumC Sharp Equality OperatorC Sharp Equals and GetHashCodeC Sharp EventsC Sharp Exception HandlingC Sharp Expression TreesC Sharp Extension MethodsC Sharp File and Stream I/OC Sharp FileSystemWatcherC Sharp Func delegatesC Sharp Function with multiple return valuesC Sharp Functional ProgrammingC Sharp Garbage Collector in .NETC Sharp Generating Random NumbersC Sharp Generic Lambda Query BuilderC Sharp GenericsC Sharp Getting Started: Json with C SharpC Sharp GuidC Sharp Handling FormatException when converting string to other typesC Sharp Hash FunctionsC Sharp ICloneableC Sharp IComparableC Sharp IDisposable interfaceC Sharp IEnumerableC Sharp ILGeneratorC Sharp ImmutabilityC Sharp Implementing Decorator Design PatternC Sharp Implementing Flyweight Design PatternC Sharp Import Google ContactsC Sharp Including Font ResourcesC Sharp IndexerC Sharp InheritanceC Sharp Initializing PropertiesC Sharp INotifyPropertyChanged interfaceC Sharp InterfacesC Sharp InteroperabilityC Sharp IQueryable interfaceC Sharp IteratorsC Sharp KeywordsC Sharp Lambda expressionsC Sharp Lambda ExpressionsC Sharp LINQ QueriesC Sharp LINQ to Objects



C Sharp String Interpolation

From WikiOD

Syntax[edit | edit source]

Remarks[edit | edit source]

String interpolation is a shorthand for the string.Format() method that makes it easier to build strings with variable and expression values inside of them.

var name = "World";
var oldWay = string.Format("Hello, {0}!", name);  // returns "Hello, World"
var newWay = $"Hello, {name}!";                   // returns "Hello, World"

Format dates in strings[edit | edit source]

var date = new DateTime(2015, 11, 11);
var str = $"It's {date:MMMM d, yyyy}, make a wish!";
System.Console.WriteLine(str);

You can also use the DateTime.ToString method to format the DateTime object. This will produce the same output as the code above.

var date = new DateTime(2015, 11, 11);
var str = date.ToString("MMMM d, yyyy");
str = "It's " + str + ", make a wish!";
Console.WriteLine(str);

Output:

It's November 11, 2015, make a wish!

Live Demo on .NET Fiddle

Live Demo using DateTime.ToString

Note: MM stands for months and mm for minutes. Be very careful when using these as mistakes can introduce bugs that may be difficult to discover.

Padding the output[edit | edit source]

String can be formatted to accept a padding parameter that will specify how many character positions the inserted string will use :

${value, padding}

NOTE: Positive padding values indicate left padding and negative padding values indicate right padding.

Left Padding[edit | edit source]

A left padding of 5 (adds 3 spaces before the value of number, so it takes up a total of 5 character positions in the resulting string.)

var number = 42;
var str = $"The answer to life, the universe and everything is {number, 5}.";
//str is "The answer to life, the universe and everything is    42.";
//                                                           ^^^^^
System.Console.WriteLine(str);

Output:

The answer to life, the universe and everything is    42.

Live Demo on .NET Fiddle

Right Padding[edit | edit source]

Right padding, which uses a negative padding value, will add spaces to the end of the current value.

var number = 42;
var str = $"The answer to life, the universe and everything is ${number, -5}.";
//str is "The answer to life, the universe and everything is 42   .";
//                                                           ^^^^^
System.Console.WriteLine(str);

Output:

The answer to life, the universe and everything is 42   .

Live Demo on .NET Fiddle

Padding with Format Specifiers[edit | edit source]

You can also use existing formatting specifiers in conjunction with padding.

var number = 42;
var str = $"The answer to life, the universe and everything is ${number, 5:f1}";
//str is "The answer to life, the universe and everything is 42.1 ";
//                                                           ^^^^^

Live Demo on .NET Fiddle

Expressions[edit | edit source]

Full expressions can also be used in interpolated strings.

var StrWithMathExpression = $"1 + 2 = {1 + 2}"; // -> "1 + 2 = 3"

string world = "world";
var StrWithFunctionCall = $"Hello, {world.ToUpper()}!"; // -> "Hello, WORLD!"

Live Demo on .NET Fiddle

Simple Usage[edit | edit source]

var name = "World";
var str = $"Hello, {name}!";
//str now contains: "Hello, World!";

Behind the scenes[edit | edit source]

Internally this

$"Hello, {name}!"

Will be compiled to something like this:

string.Format("Hello, {0}!", name);

Formatting numbers in strings[edit | edit source]

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 withThreeDecimalPlaces = $"Exactly {decimalValue:F3}";
// String value is "Exactly 120.500"

var integerValue = 57;

var prefixedIfNecessary = $"{integerValue:D5}";
// String value is "00057"

Live Demo on .NET Fiddle

Credit:Stack_Overflow_Documentation