To avoid the hardcoded string in the code, we make use of an operator called nameof operator in C# which accepts the elements of the code names and returns the same element’s string literal and a class name, all the members of the class like variables, methods, constants can be passed as parameters to the nameof operator and a string literal is returned and this string literal returned from using nameof operator is a special kind of string literal because the given name is checked by the compiler to see if something exists by that name and if it is referred by the visual studio.
The syntax of the nameof operator in C# is as follows:
nameof(Expression)
Code:
using System; //a namespace called name is defined namespace Name { //a class called check is defined class Check { //main method is called static void Main(string[] args) { //nameof operator is used Console.WriteLine(nameof(Name)); Console.WriteLine(nameof(Check)); Console.WriteLine(nameof(Check.Main)); Console.WriteLine(nameof(Main)); Console.WriteLine(nameof(args)); } } }
Output:
In the above program, a namespace called name is defined. Then a class called check is defined. Then the main method is called. Then the nameof operator is used to identify the name of the namespace, name of the program, the main method, and its arguments. The point of using the nameof operator here is that if any of the items of the code names are changed, then we must change all the nameof operators used in the code otherwise failure of build occurs. If we are using the nameof operator, then the compiler will point out the bugs otherwise these will be found when the program is used in production.
Here are the following examples mention below
Program to demonstrate the nameof operator.
Code:
using System; //a namespace called Features is defined namespace Features { //a class called Example is defined class Example { //an integer array called array is defined int[] array = new int[5]; //main method is called public static void Main(string[] args) { //an instance of the class Example is created Example ex1 = new Example(); //try and catch block is defined try { //the showop method is called using the instance of the Example class ex1.showop(ex1.array); } catch(Exception e) { Console.WriteLine(e.Message); //the method that throws the exception is displayed Console.WriteLine("The name of the method is: "+nameof(ex1.showop)); } } int showop(int[] x) { x[5] = 12; return x[5]; } } }
Output:
In the above program, a namespace called Features is defined. Then a class called Example is defined. Then an integer array called array is defined. Then the main method is called. Then an instance of the class Example is created. Then try and catch block is defined. Then the showop method is called using the instance of the Example class. Then the method that throws the exception is displayed. The point of using the nameof operator here is that if any of the items of the code names are changed, then we must change all the nameof operators used in the code otherwise failure of build occurs. If we are using the nameof operator, then the compiler will point out the bugs otherwise these will be found when the program is used in production.
Program to demonstrate the use of the nameof operator.
Code:
using System; //a class called check is defined public class Check { //DateTime Function is used to find the current data and To LocalTime private static DateTime Today = DateTime.Now; //get and set functions are used public string Name { get; set; } //main method is called public static void Main(string[] args) { //a variable called local_Time is defined to obtain the current date and To LocalTime var local_Time = DateTime.Now.ToLocalTime(); //nameof operator is used to obtain the local_time, args, Systme information, main method, program name. Console.WriteLine(nameof(local_Time)); Console.WriteLine(nameof(args)); Console.WriteLine(nameof(System.IO)); Console.WriteLine(nameof(Main)); Console.WriteLine(nameof(Check)); Console.WriteLine(nameof(Check.Today)); Console.WriteLine(nameof(Check.Name)); } }
Output:
In the above program, a class called Check is defined. Then the DateTime Function is used to find the current date and LocalTime. Then get and set functions are used. Then the main method is called. Then a variable called local_Time is defined to obtain the current date and LocalTime. Then the nameof operator is used to obtain the local_time, args, System information, main method, program name. The point of using the nameof operator here is that if any of the items of the code names are changed, then we must change all the nameof operators used in the code otherwise failure of build occurs. If we are using the nameof operator, then the compiler will point out the bugs otherwise these will be found when the program is used in production.
Program to demonstrate the nameof operator.
Code:
using System; //a class called check is defined class Check { //a method called taste is defined static void Taste(int argu) { //nameof operator is used Console.WriteLine(nameof(argu)); Console.WriteLine(argu); //nameof operator is used on the defined variable var plane = "Shobha"; Console.WriteLine(nameof(plane)); } //main method is called static void Main() { //the method taste is called along with passing a parameter Taste(200); } }
Output:
In the above program, a class called check is defined. Then a method called taste is defined within the class in which the nameof operator is used. Then a variable is defined on which the nameof operator is used again. Then the main method is called from which the defined method Taste is called along with passing the parameter. The point of using the nameof operator here is that if any of the items of the code names are changed, then we must change all the nameof operators used in the code otherwise failure of build occurs. If we are using the nameof operator, then the compiler will point out the bugs otherwise these will be found when the program is used in production.
In diesem Tutorial verstehen wir das Konzept des Operators „nameof“ in C# durch Definition, die Syntax des Operators „nameof“ in C#, die Funktionsweise des Operators „nameof“ in C# anhand von Beispielen und deren Ausgaben.
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