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This page is specific to
Microsoft Visual Studio 2010/.NET Framework 4

Other versions are also available for the following:
.NET Framework Class Library
Single Structure

Represents a single-precision floating-point number.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)
 Syntax
Visual Basic 
<SerializableAttribute> _
<ComVisibleAttribute(True)> _
Public Structure Single _
    Implements IComparable, IFormattable, IConvertible, IComparable(Of Single),  _
    IEquatable(Of Single)
C# 
[SerializableAttribute]
[ComVisibleAttribute(true)]
public struct Single : IComparable, IFormattable, 
    IConvertible, IComparable<float>, IEquatable<float>
Visual C++ 
[SerializableAttribute]
[ComVisibleAttribute(true)]
public value class Single : IComparable, 
    IFormattable, IConvertible, IComparable<float>, IEquatable<float>
F# 
[<Sealed>]
[<SerializableAttribute>]
[<ComVisibleAttribute(true)>]
type Single =  
    struct
        interface IComparable
        interface IFormattable
        interface IConvertible
        interface IComparable<float32>
        interface IEquatable<float32>
    end

The Single type exposes the following members.

 Methods
  NameDescription
Public methodSupported by the XNA FrameworkCompareTo(Object)Compares this instance to a specified object and returns an integer that indicates whether the value of this instance is less than, equal to, or greater than the value of the specified object.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryCompareTo(Single)Compares this instance to a specified single-precision floating-point number and returns an integer that indicates whether the value of this instance is less than, equal to, or greater than the value of the specified single-precision floating-point number.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryEquals(Object)Returns a value indicating whether this instance is equal to a specified object. (Overrides ValueType..::.Equals(Object).)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryEquals(Single)Returns a value indicating whether this instance and a specified Single object represent the same value.
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibraryFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryGetHashCodeReturns the hash code for this instance. (Overrides ValueType..::.GetHashCode()()().)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodSupported by the XNA FrameworkGetTypeCodeReturns the TypeCode for value type Single.
Public methodStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryIsInfinityReturns a value indicating whether the specified number evaluates to negative or positive infinity.
Public methodStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryIsNaNReturns a value indicating whether the specified number evaluates to not a number (NaN).
Public methodStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryIsNegativeInfinityReturns a value indicating whether the specified number evaluates to negative infinity.
Public methodStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryIsPositiveInfinityReturns a value indicating whether the specified number evaluates to positive infinity.
Protected methodSupported by the XNA FrameworkSupported by Portable Class LibraryMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodStatic memberSupported by the XNA FrameworkParse(String)Converts the string representation of a number to its single-precision floating-point number equivalent.
Public methodStatic memberSupported by the XNA FrameworkParse(String, NumberStyles)Converts the string representation of a number in a specified style to its single-precision floating-point number equivalent.
Public methodStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryParse(String, IFormatProvider)Converts the string representation of a number in a specified culture-specific format to its single-precision floating-point number equivalent.
Public methodStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryParse(String, NumberStyles, IFormatProvider)Converts the string representation of a number in a specified style and culture-specific format to its single-precision floating-point number equivalent.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryToString()()()Converts the numeric value of this instance to its equivalent string representation. (Overrides ValueType..::.ToString()()().)
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryToString(IFormatProvider)Converts the numeric value of this instance to its equivalent string representation using the specified culture-specific format information.
Public methodSupported by the XNA FrameworkToString(String)Converts the numeric value of this instance to its equivalent string representation, using the specified format.
Public methodSupported by the XNA FrameworkSupported by Portable Class LibraryToString(String, IFormatProvider)Converts the numeric value of this instance to its equivalent string representation using the specified format and culture-specific format information.
Public methodStatic memberTryParse(String, Single%)Converts the string representation of a number to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.
Public methodStatic memberSupported by Portable Class LibraryTryParse(String, NumberStyles, IFormatProvider, Single%)Converts the string representation of a number in a specified style and culture-specific format to its single-precision floating-point number equivalent. A return value indicates whether the conversion succeeded or failed.
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 Operators
  NameDescription
Public operatorStatic memberEqualityReturns a value that indicates whether two specified Single values are equal.
Public operatorStatic memberGreaterThanReturns a value that indicates whether a specified Single value is greater than another specified Single value.
Public operatorStatic memberGreaterThanOrEqualReturns a value that indicates whether a specified Single value is greater than or equal to another specified Single value.
Public operatorStatic memberInequalityReturns a value that indicates whether two specified Single values are not equal.
Public operatorStatic memberLessThanReturns a value that indicates whether a specified Single value is less than another specified Single value.
Public operatorStatic memberLessThanOrEqualReturns a value that indicates whether a specified Single value is less than or equal to another specified Single value.
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 Fields
  NameDescription
Public fieldStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryEpsilonRepresents the smallest positive Single value that is greater than zero. This field is constant.
Public fieldStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryMaxValueRepresents the largest possible value of Single. This field is constant.
Public fieldStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryMinValueRepresents the smallest possible value of Single. This field is constant.
Public fieldStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryNaNRepresents not a number (NaN). This field is constant.
Public fieldStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryNegativeInfinityRepresents negative infinity. This field is constant.
Public fieldStatic memberSupported by the XNA FrameworkSupported by Portable Class LibraryPositiveInfinityRepresents positive infinity. This field is constant.
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 Explicit Interface Implementations
  NameDescription
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToBooleanInfrastructure. For a description of this member, see IConvertible..::.ToBoolean.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToByteInfrastructure. For a description of this member, see IConvertible..::.ToByte.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToCharInfrastructure. This conversion is not supported. Attempting to use this method throws an InvalidCastException.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToDateTimeInfrastructure. This conversion is not supported. Attempting to use this method throws an InvalidCastException.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToDecimalInfrastructure. For a description of this member, see IConvertible..::.ToDecimal.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToDoubleInfrastructure. For a description of this member, see IConvertible..::.ToDouble.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToInt16Infrastructure. For a description of this member, see IConvertible..::.ToInt16.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToInt32Infrastructure. For a description of this member, see IConvertible..::.ToInt32.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToInt64Infrastructure. For a description of this member, see IConvertible..::.ToInt64.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToSByteInfrastructure. For a description of this member, see IConvertible..::.ToSByte.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToSingleInfrastructure. For a description of this member, see IConvertible..::.ToSingle.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToTypeInfrastructure. For a description of this member, see IConvertible..::.ToType.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToUInt16Infrastructure. For a description of this member, see IConvertible..::.ToUInt16.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToUInt32Infrastructure. For a description of this member, see IConvertible..::.ToUInt32.
Explicit interface implemetationPrivate methodSupported by the XNA FrameworkIConvertible..::.ToUInt64Infrastructure. For a description of this member, see IConvertible..::.ToUInt64.
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 Remarks

The Single value type represents a single-precision 32-bit number with values ranging from negative 3.402823e38 to positive 3.402823e38, as well as positive or negative zero, PositiveInfinity, NegativeInfinity, and not a number (NaN).

Single complies with the IEC 60559:1989 (IEEE 754) standard for binary floating-point arithmetic.

Single provides methods to compare instances of this type, convert the value of an instance to its string representation, and convert the string representation of a number to an instance of this type. For information about how format specification codes control the string representation of value types, see Formatting Types, Standard Numeric Format Strings, and Custom Numeric Format Strings.

Using Floating-Point Numbers

When performing binary operations, if one of the operands is a floating-point type, Single or Double, then the other operand is required to be an integral type or a floating-point type. The operation is evaluated as follows:

  • If one of the operands is of an integral type, then that operand is converted to the floating-point type of the other operand.

  • Then, if either of the operands is Double, the other operand is converted to Double, and the operation is performed using at least the range and precision of the Double. For numeric operations, the type of the result is Double.

  • Otherwise, the operation is performed using at least the range and precision of the Single type and, for numeric operations, the type of the result is Single.

The floating-point operators, including the assignment operators, do not throw exceptions. Instead, in exceptional situations the result of a floating-point operation is zero, infinity, or NaN, as described below:

  • If the result of a floating-point operation is too small for the destination format, the result of the operation is zero.

  • If the magnitude of the result of a floating-point operation is too large for the destination format, the result of the operation is PositiveInfinity or NegativeInfinity, as appropriate for the sign of the result.

  • If a floating-point operation is invalid, the result of the operation is NaN.

  • If one or both operands of a floating-point operation are NaN, the result of the operation is NaN.

Floating-Point Values and Loss of Precision

Remember that a floating-point number can only approximate a decimal number, and that the precision of a floating-point number determines how accurately that number approximates a decimal number. By default, a Single value contains only 7 decimal digits of precision, although a maximum of 9 digits is maintained internally. The precision of a floating-point number has several consequences:

  • Two floating-point numbers that appear equal for a particular precision might not compare equal because their least significant digits are different.

  • A mathematical or comparison operation that uses a floating-point number might not yield the same result if a decimal number is used because the floating-point number might not exactly approximate the decimal number.

  • A value might not roundtrip if a floating-point number is involved. A value is said to roundtrip if an operation converts an original floating-point number to another form, an inverse operation transforms the converted form back to a floating-point number, and the final floating-point number is equal to the original floating-point number. The roundtrip might fail because one or more least significant digits are lost or changed in a conversion.

 Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library
 Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
 Thread Safety

All members of this type are thread safe. Members that appear to modify instance state actually return a new instance initialized with the new value. As with any other type, reading and writing to a shared variable that contains an instance of this type must be protected by a lock to guarantee thread safety.
 See Also

Reference

System Namespace
Decimal
Double
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Examples of Currency Value Types With a Decimal Point      Nevin Janzen   |   Edit   |   Show History 
using System;
using System.Globalization;
using System.Runtime;
using System.Runtime.Serialization;
using System.Security;


// currency value types: 

namespace Currency
{
    [Serializable]
    public struct CAD : IComparable, IFormattable, IConvertible, ISerializable, IComparable<CAD>, IEquatable<CAD>
    {
        /* constructors... */

        /* properties */
        public long WholeNumbers
        {
            get;
        }
        public long DigitsAfterDecimal
        {
            get;
        }
        // other properties and fields...

        /* operators */
        public static CAD operator +(CAD cad1, CAD cad2);
        public static CAD operator +(CAD cad, USD usd);
        public static CAD operator +(CAD cad, decimal m);
        public static CAD operator +(CAD cad, double d);
        public static CAD operator +(CAD cad, float f);
        public static CAD operator +(CAD cad, object o);
        // other operators...

        /* other methods... */
    }

    [Serializable]
    public struct USD : IComparable, IFormattable, IConvertible, ISerializable, IComparable<USD>, IEquatable<USD>
    {
        /* constructors... */

        /* properties */
        public long WholeNumbers
        {
            get;
        }
        public long DigitsAfterDecimal
        {
            get;
        }
        // other properties and fields...

        /* operators... */

        /* other methods... */
    }
    /* other structs of currency value types... */
}
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