string and System.String
In C#, string and String both represent the same data type, which is used to store a sequence of characters. The main difference between them lies in their declaration and usage.
string (with a lowercase 's')
- string is an alias for the .NET framework's System.String data type.
- It is a reference type, meaning it is stored on the managed heap, and its variable holds a reference to the actual memory location where the string data resides.
- In C#, it is conventionally recommended to use string (lowercase) instead of String (uppercase).
string firstName = "Smith";
string lastName = "Warrier";
String (with an uppercase 'S')
- String is the fully qualified name of the .NET framework's System.String data type.
- It is also a reference type and used to represent a sequence of characters in the same way as string.
String message = "Hello, World!";
As you can see, there is no practical difference between using string and String in C#. Both are interchangeable, and developers typically prefer using string due to its lowercase convention, which aligns with the general naming guidelines in C#.
Here's a more comprehensive example illustrating the interchangeable usage of string and String:
using System;
class Program
{
static void Main()
{
// Using 'string' (lowercase) to declare variables
string name1 = "Alice";
string name2 = "Bob";
// Using 'String' (uppercase) to declare variables
String greeting1 = "Hello, " + name1;
String greeting2 = "Hello, " + name2;
// Using 'string' in method parameters and return type
string fullName = ConcatenateNames(name1, name2);
Console.WriteLine(fullName); // Output: AliceBob
// Using 'String' in method parameters and return type
String fullGreeting = GenerateGreeting(greeting1, greeting2);
Console.WriteLine(fullGreeting); // Output: Hello, AliceHello, Bob
}
static string ConcatenateNames(string firstName, string lastName)
{
return firstName + lastName;
}
static String GenerateGreeting(String greeting1, String greeting2)
{
return greeting1 + greeting2;
}
}
Conclusion
It's important to emphasize that both string and String are interchangeable, and developers generally use string due to the standard naming conventions in C#. NEXT..... Dictionary in C#