Difference between string and stringbuilder?

[Quique]

I am attending lecture for C# and it is new language for me. I can not understand difference between string stringbuilder. I know this terms are related to the string but this information is not enough. Someone help me to understand string and stringbuilder. Please give me some example that based on it.

[Modifier]

Imports System.Text
 
public class Test

   public Shared Sub Main
        Const ADD As String = "1234567890"
        Dim num As Long = 1000
        Dim start As DateTime
        Dim stop As DateTime
        Dim elapsed As TimeSpan
        Dim txt1 As String
        Dim string_builder As New StringBuilder

        txt = ""
        start = Now
        For i As Long = 1 To num
            txt1 = txt1 & ADD
        Next i
        stop= Now
        elapsed = stop.Subtract(start)
        Console.WriteLine(elapsed.TotalSeconds.ToString("0.000000"))

        txt = ""
        start = Now
        For i As Long = 1 To num
            string_builder.Append(ADD)
        Next i
        txt1 = string_builder.ToString()
        stop = Now
        elapsed = stop.Subtract(start)
        Console.WriteLine(elapsed.TotalSeconds.ToString("0.000000"))

   End Sub

End class

This code will help you.

[MindSpace]

Difference between String ans stringbuilder is as follows-
string-
1.string is handled using this class.
2.concatenation method is used to concatenate two strings.
3.For concatenating two string string object is used.
4.Strings are immutable.

String Builder-
1.This is also the class used to handle strings.
2.Append method is used to concatenate two strings.
3.Stringbuilder object is used.
4.Existing string is used for insertion.

[opaper]

String are Immutable. If you try to change the string then it creates a new string and the old string will be ready for garbage collection. String is immitable, StringBuilder is mutable. When StringBuilder instantiated, it make a new string with predefined capacity and it can accodomate string without creating new memory location for the string.

[Reegan]

Once a string object is created then they cannot changed hence they called immutable. If we used one of the method of a string class then new string object is created.

For example: String strSen = “hello”;
When we try to concatenate any other words along with strSen variable, it does not modify the strSen variable, instead of it creates a new string.
For example: strSen = strSen + “Hello”;

[absolute55]

In string concatenation method StringBuilder provide better performance than string object. StringBuilder is mutable class which allow to modify the original value without creating a new object. You can use StringBuilder Append() method for concatenation.