StringBuilder.Equals Method

Definition

Namespace:

System.Text

Assembly:

System.Runtime.dll

Overloads

Equals(ReadOnlySpan<Char>)	Returns a value indicating whether the characters in this instance are equal to the characters in a specified read-only character span.
Equals(StringBuilder)	Returns a value indicating whether this instance is equal to a specified object.

Equals(ReadOnlySpan<Char>)

Source:

StringBuilder.cs

Returns a value indicating whether the characters in this instance are equal to the characters in a specified read-only character span.

public:
 bool Equals(ReadOnlySpan<char> span);

public bool Equals (ReadOnlySpan<char> span);

override this.Equals : ReadOnlySpan<char> -> bool

Public Function Equals (span As ReadOnlySpan(Of Char)) As Boolean

Parameters

span

ReadOnlySpan<Char>

The character span to compare with the current instance.

Returns

Boolean

true if the characters in this instance and span are the same; otherwise, false.

Remarks

The Equals method performs an ordinal comparison to determine whether the characters in the current instance and span are equal.

Equals(StringBuilder)

Source:

StringBuilder.cs

Returns a value indicating whether this instance is equal to a specified object.

public:
 bool Equals(System::Text::StringBuilder ^ sb);

public bool Equals (System.Text.StringBuilder? sb);

override this.Equals : System.Text.StringBuilder -> bool

Public Function Equals (sb As StringBuilder) As Boolean

Parameters

sb

StringBuilder

An object to compare with this instance, or null.

Returns

Boolean

true if this instance and sb have equal string, Capacity, and MaxCapacity values; otherwise, false.

Examples

The following code uses the Equals method to check whether two StringBuilder objects are equal. The method is called repeatedly after small changes are made to each object, and the results are displayed to the console.

using namespace System;
using namespace System::Text;
int main()
{
   StringBuilder^ sb1 = gcnew StringBuilder( "abc" );
   StringBuilder^ sb2 = gcnew StringBuilder( "abc",16 );
   Console::WriteLine();
   Console::WriteLine( "a1) sb1->Length = {0}, sb1->Capacity = {1}", sb1->Length, sb1->Capacity );
   Console::WriteLine( "a2) sb2->Length = {0}, sb2->Capacity = {1}", sb2->Length, sb2->Capacity );
   Console::WriteLine( "a3) sb1 = \"{0}\", sb2 = \"{1}\"", sb1, sb2 );
   Console::WriteLine( "a4) sb1 equals sb2: {0}", sb1->Equals( sb2 ) );
   Console::WriteLine();
   Console::WriteLine( "Ensure sb1 has a capacity of at least 50 characters." );
   sb1->EnsureCapacity( 50 );
   Console::WriteLine();
   Console::WriteLine( "b1) sb1->Length = {0}, sb1->Capacity = {1}", sb1->Length, sb1->Capacity );
   Console::WriteLine( "b2) sb2->Length = {0}, sb2->Capacity = {1}", sb2->Length, sb2->Capacity );
   Console::WriteLine( "b3) sb1 = \"{0}\", sb2 = \"{1}\"", sb1, sb2 );
   Console::WriteLine( "b4) sb1 equals sb2: {0}", sb1->Equals( sb2 ) );
   Console::WriteLine();
   Console::WriteLine( "Set the length of sb1 to zero." );
   Console::WriteLine( "Set the capacity of sb2 to 51 characters." );
   sb1->Length = 0;
   sb2->Capacity = 51;
   Console::WriteLine();
   Console::WriteLine( "c1) sb1->Length = {0}, sb1->Capacity = {1}", sb1->Length, sb1->Capacity );
   Console::WriteLine( "c2) sb2->Length = {0}, sb2->Capacity = {1}", sb2->Length, sb2->Capacity );
   Console::WriteLine( "c3) sb1 = \"{0}\", sb2 = \"{1}\"", sb1, sb2 );
   Console::WriteLine( "c4) sb1 equals sb2: {0}", sb1->Equals( sb2 ) );
}

/*
The example displays the following output:

a1) sb1->Length = 3, sb1->Capacity = 16
a2) sb2->Length = 3, sb2->Capacity = 16
a3) sb1 = "abc", sb2 = "abc"
a4) sb1 equals sb2: True

Ensure sb1 has a capacity of at least 50 characters.

b1) sb1->Length = 3, sb1->Capacity = 50
b2) sb2->Length = 3, sb2->Capacity = 16
b3) sb1 = "abc", sb2 = "abc"
b4) sb1 equals sb2: False

Set the length of sb1 to zero.
Set the capacity of sb2 to 51 characters.

c1) sb1->Length = 0, sb1->Capacity = 50
c2) sb2->Length = 3, sb2->Capacity = 51
c3) sb1 = "", sb2 = "abc"
c4) sb1 equals sb2: False
*/

using System;
using System.Text;

class Sample
{
    public static void Main()
    {
    StringBuilder sb1 = new StringBuilder("abc");
    StringBuilder sb2 = new StringBuilder("abc", 16);

    Console.WriteLine();
    Console.WriteLine("a1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity);
    Console.WriteLine("a2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity);
    Console.WriteLine("a3) sb1.ToString() = \"{0}\", sb2.ToString() = \"{1}\"",
                           sb1.ToString(),       sb2.ToString());
    Console.WriteLine("a4) sb1 equals sb2: {0}", sb1.Equals(sb2));

    Console.WriteLine();
    Console.WriteLine("Ensure sb1 has a capacity of at least 50 characters.");
    sb1.EnsureCapacity(50);

    Console.WriteLine();
    Console.WriteLine("b1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity);
    Console.WriteLine("b2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity);
    Console.WriteLine("b3) sb1.ToString() = \"{0}\", sb2.ToString() = \"{1}\"",
                           sb1.ToString(),       sb2.ToString());
    Console.WriteLine("b4) sb1 equals sb2: {0}", sb1.Equals(sb2));

    Console.WriteLine();
    Console.WriteLine("Set the length of sb1 to zero.");
    Console.WriteLine("Set the capacity of sb2 to 51 characters.");
    sb1.Length = 0;
    sb2.Capacity = 51;

    Console.WriteLine();
    Console.WriteLine("c1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity);
    Console.WriteLine("c2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity);
    Console.WriteLine("c3) sb1.ToString() = \"{0}\", sb2.ToString() = \"{1}\"",
                           sb1.ToString(),       sb2.ToString());
    Console.WriteLine("c4) sb1 equals sb2: {0}", sb1.Equals(sb2));
    }
}
/*
The example displays the following output:

a1) sb1.Length = 3, sb1.Capacity = 16
a2) sb2.Length = 3, sb2.Capacity = 16
a3) sb1.ToString() = "abc", sb2.ToString() = "abc"
a4) sb1 equals sb2: True

Ensure sb1 has a capacity of at least 50 characters.

b1) sb1.Length = 3, sb1.Capacity = 50
b2) sb2.Length = 3, sb2.Capacity = 16
b3) sb1.ToString() = "abc", sb2.ToString() = "abc"
b4) sb1 equals sb2: False

Set the length of sb1 to zero.
Set the capacity of sb2 to 51 characters.

c1) sb1.Length = 0, sb1.Capacity = 50
c2) sb2.Length = 3, sb2.Capacity = 51
c3) sb1.ToString() = "", sb2.ToString() = "abc"
c4) sb1 equals sb2: False
*/

open System.Text

let sb1 = StringBuilder "abc"
let sb2 = StringBuilder("abc", 16)

printfn $"a1) sb1.Length = {sb1.Length}, sb1.Capacity = {sb1.Capacity}"
printfn $"a2) sb2.Length = {sb2.Length}, sb2.Capacity = {sb2.Capacity}"
printfn $"a3) sb1.ToString() = \"{sb1}\", sb2.ToString() = \"{sb2}\""
printfn $"a4) sb1 equals sb2: {sb1.Equals sb2}"

printfn "\nEnsure sb1 has a capacity of at least 50 characters."
sb1.EnsureCapacity 50 |> ignore

printfn $"\nb1) sb1.Length = {sb1.Length}, sb1.Capacity = {sb1.Capacity}"
printfn $"b2) sb2.Length = {sb2.Length}, sb2.Capacity = {sb2.Capacity}"
printfn $"b3) sb1.ToString() = \"{sb1}\", sb2.ToString() = \"{sb2}\""
printfn $"b4) sb1 equals sb2: {sb1.Equals sb2}"

printfn "\nSet the length of sb1 to zero."
printfn "Set the capacity of sb2 to 51 characters."
sb1.Length <- 0
sb2.Capacity <- 51

printfn $"\nc1) sb1.Length = {sb1.Length}, sb1.Capacity = {sb1.Capacity}"
printfn $"c2) sb2.Length = {sb2.Length}, sb2.Capacity = {sb2.Capacity}"
printfn $"c3) sb1.ToString() = \"{sb1}\", sb2.ToString() = \"{sb2}\""
printfn $"c4) sb1 equals sb2: {sb1.Equals sb2}"

// The example displays the following output:
//       a1) sb1.Length = 3, sb1.Capacity = 16
//       a2) sb2.Length = 3, sb2.Capacity = 16
//       a3) sb1.ToString() = "abc", sb2.ToString() = "abc"
//       a4) sb1 equals sb2: True
//
//       Ensure sb1 has a capacity of at least 50 characters.
//       
//       b1) sb1.Length = 3, sb1.Capacity = 50
//       b2) sb2.Length = 3, sb2.Capacity = 16
//       b3) sb1.ToString() = "abc", sb2.ToString() = "abc"
//       b4) sb1 equals sb2: False
//       
//       Set the length of sb1 to zero.
//       Set the capacity of sb2 to 51 characters.
//       
//       c1) sb1.Length = 0, sb1.Capacity = 50
//       c2) sb2.Length = 3, sb2.Capacity = 51
//       c3) sb1.ToString() = "", sb2.ToString() = "abc"
//       c4) sb1 equals sb2: False

Imports System.Text

Class Sample
   Public Shared Sub Main()
      Dim sb1 As New StringBuilder("abc")
      Dim sb2 As New StringBuilder("abc", 16)
      
      Console.WriteLine()
      Console.WriteLine("a1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity)
      Console.WriteLine("a2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity)
      Console.WriteLine("a3) sb1.ToString() = ""{0}"", sb2.ToString() = ""{1}""", _
                             sb1.ToString(),           sb2.ToString())
      Console.WriteLine("a4) sb1 equals sb2: {0}", sb1.Equals(sb2))
      
      Console.WriteLine()
      Console.WriteLine("Ensure sb1 has a capacity of at least 50 characters.")
      sb1.EnsureCapacity(50)
      
      Console.WriteLine()
      Console.WriteLine("b1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity)
      Console.WriteLine("b2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity)
      Console.WriteLine("b3) sb1.ToString() = ""{0}"", sb2.ToString() = ""{1}""", _
                             sb1.ToString(),           sb2.ToString())
      Console.WriteLine("b4) sb1 equals sb2: {0}", sb1.Equals(sb2))
      
      Console.WriteLine()
      Console.WriteLine("Set the length of sb1 to zero.")
      Console.WriteLine("Set the capacity of sb2 to 51 characters.")
      sb1.Length = 0
      sb2.Capacity = 51
      
      Console.WriteLine()
      Console.WriteLine("c1) sb1.Length = {0}, sb1.Capacity = {1}", sb1.Length, sb1.Capacity)
      Console.WriteLine("c2) sb2.Length = {0}, sb2.Capacity = {1}", sb2.Length, sb2.Capacity)
      Console.WriteLine("c3) sb1.ToString() = ""{0}"", sb2.ToString() = ""{1}""", _
                             sb1.ToString(),           sb2.ToString())
      Console.WriteLine("c4) sb1 equals sb2: {0}", sb1.Equals(sb2))
   End Sub 
End Class
'The example displays the following output:
'       a1) sb1.Length = 3, sb1.Capacity = 16
'       a2) sb2.Length = 3, sb2.Capacity = 16
'       a3) sb1.ToString() = "abc", sb2.ToString() = "abc"
'       a4) sb1 equals sb2: True
'       
'       Ensure sb1 has a capacity of at least 50 characters.
'       
'       b1) sb1.Length = 3, sb1.Capacity = 50
'       b2) sb2.Length = 3, sb2.Capacity = 16
'       b3) sb1.ToString() = "abc", sb2.ToString() = "abc"
'       b4) sb1 equals sb2: False
'       
'       Set the length of sb1 to zero.
'       Set the capacity of sb2 to 51 characters.
'       
'       c1) sb1.Length = 0, sb1.Capacity = 50
'       c2) sb2.Length = 3, sb2.Capacity = 51
'       c3) sb1.ToString() = "", sb2.ToString() = "abc"
'       c4) sb1 equals sb2: False

Remarks

.NET Framework and .NET Core 2.2 and previous versions: The current instance and sb are equal if they have equal string, Capacity, and MaxCapacity values. The Equals method uses ordinal comparison to determine whether the strings are equal.

.NET Core 3.0 and later versions: The current instance and sb are equal if the strings assigned to both StringBuilder objects are the same. To determine equality, the Equals method uses ordinal comparison. The Capacity and MaxCapacity property values are not used in the comparison.