Literals, Punctuators, Operators, Predefined and Custom Types in C#

Goud.Kv
Posted by in C# category on for Beginner level | Points: 250 | Views : 8417 red flag

As we know that now a days C# plays a major role in most of the Web technologies to write the server side code, Ex: ASP.NET, ASP.NET MVC etc., Lets see Language Basics of C# in this chapter.
Recommendation
Read Identifiers and Keywords in C# Programming before this article.

Introduction

So far we have seen Identifiers and Keywords of C# in previous article and let's see some more basics of C# Language in here.

Objective

The main objective of this article is to learn literals, operators, punctuators etc. in C# Programming.

Description

Let's recall the example code that we had in the previous article to explain few more things.
using System;

class Addition 
  {  
    static void Main()  
      {
        int a = 15 + 25;
        Console.WriteLine (x);
      } 
  }
Literals:
Literals are the primitive pieces of data that are embedded into a program. i.e. representation of source code.
In the above example code, 15 and 25 are the literals.

There are so many types of literals are there in C#. They are.
  • Integer-literal - These are used to write values of type int, longuint, ulong etc. with decimal and hexadecimal forms.

  • Boolean-literal - Boolean means true or false. So there are two boolean literals: true and false.

  • Character-literal - These literals represents a single character in quotes. Ex: 'x'.

  • String-literal - There are two types of string literals in C#. They are regular and verbatim. Regular means zero or more characters mentioned in double quotes, Ex: "Welcome". Verbatim means @ character followed by double quoted character, Ex: @"Welcome".

  • Real-literal - These are used to write the values with type of float, decimal and double.
  • Null-literal - It is simply a null type i.e. null.
Punctuators:
Punctuators are used to group or separate the part of code. These helps to demarcate the program structure.
In the above code, {, } and ; are the punctuators.
  • Braces are used to group the multiple statements into a separate block.

  • Semicolon is used to terminate the statement.
Operators:
It combines the expressions or transforms them.
Exa + b. 
'+' is called as an operator which combines a and b and performs addition.
In the above example code, ., (), + and = are the operators.

There are several kinds of operators are there in C# which does different operations based on the operands(literals).

Type Basics

Type defines a blueprint for our values. Ex: Type of literals that we used in the above code.
There is something called variable which is a storage location that can handle different values over time.
'a' is known as the variable in above program which locates the value.

Predefined Types:
These are specially supported by the compiler.
In the above code, 'int' is a predefined type and is used to represent the Integer set that fit into 32 bits of memory.
int a = 15 + 25;
This will perform the addition (Arithmetic function).

There are some more predefined types say bool, string etc.
  • string represents a sequence of characters. Ex: "DotNetFunda", "KidsFunda".
    Example code using string,
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace Hello
    {
        class Program
        {
            static void Main()
            {
                string msg = "Hello, Welcome to C#";
                string upperMsg = msg.ToUpper();
                Console.WriteLine(upperMsg);
    
                double a = 5.0;
                msg = msg + " " + a.ToString();
                Console.WriteLine(msg);
            }
        }
    }
    The output of the above program looks like,


  • bool is used for two possible values either true or false. This is mostly used with if statement to conditionally branch the flow of execution.
    Observe the below example code with bool type in it,
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Threading.Tasks;
    
    namespace Hello
    {
        class Program
        {
            static void Main()
            {
                bool val = true;
                if (val)
                {
                    Console.WriteLine("This comes on the screen");
                }
                else 
                {
                    Console.WriteLine("This doesn't comes on the screen");
                }
            }
        }
    }
    Now press Ctrl + F5 and run this code. You will see that only true value is printed on the Console.

Custom Types:
Custom types means building Complex types from Primitive types. Observe the below example program in which we are using Custom types.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Hello
{
    public class Test {  
        int x; // This variable is called as Field 
 
        // This is a Constructor
        public Test(int y) 
        {
            x = y; 
        }  
  
        // Addition Method
        public int Add(int z)
        {
            return x + z;
        }
    }

    class Program
    {
         static void Main()  {    
             Test a = new Test (10); // Object
             Console.WriteLine(a.Add(5)); // 10 + 5 = 15
             
             Test b  = new Test (20); // Object      
             Console.WriteLine (b.Add(10)); // 20 + 10 = 30
             Console.WriteLine (a.Add(b.Add(5))); // 10 + (20 + 5) = 35
         } 
    }
}
In the above code, we have a Constructor (Test) and a function (Add). We have created objects a and b in the main class.
Now press Ctrl + F5 and see the check the output of this program which may look like,


Conclusion

In this article we have seen Literals, Punctuators and Operators in C#. And also covered Predefined and Custom types with examples. Hope you enjoyed it. 

Thanks for reading.

Regards,
Krishna.

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About the Author

Goud.Kv
Full Name: Krishna Vamshi Goud
Member Level: Gold
Member Status: Member,MVP
Member Since: 2/12/2014 2:34:09 AM
Country: India
Thanks & Regards, Krishna


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