BigInteger Explicit Conversion (BigInteger to Single)

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Defines an explicit conversion of a BigInteger object to a single-precision floating-point value.

Namespace:  System.Numerics
Assembly:  System.Numerics (in System.Numerics.dll)

Syntax

'Declaration
Public Shared Narrowing Operator CType ( _
    value As BigInteger _
) As Single
public static explicit operator float (
    BigInteger value
)

Parameters

Return Value

Type: System.Single
An object that contains the closest possible representation of the value parameter.

Remarks

The overloads of the Explicit(Decimal to BigInteger) method define the types to which or from which a BigInteger object can be converted. Language compilers do not perform this conversion automatically because it can involve data loss or a loss of precision. Instead, they perform the conversion only if a casting operator (in C#) or a conversion function (such as CType or CSng in Visual Basic) is used. Otherwise, they display a compiler error.

Because the BigInteger value can be outside the range of the Single data type, this operation is a narrowing conversion. If the conversion is unsuccessful, it does not throw an OverflowException. Instead, if the BigInteger value is less than Single.MinValue, the resulting Single value is Single.NegativeInfinity. If the BigInteger value is greater than Single.MaxValue, the resulting Single value is Single.PositiveInfinity.

The conversion of a BigInteger to a Single may involve a loss of precision. In some cases, the loss of precision may cause the casting or conversion operation to succeed even if the BigInteger value is outside the range of the Single data type. The following example provides an illustration. It assigns the maximum value of a Single to two BigInteger variables, increments one BigInteger variable by 9.999e291, and tests the two variables for equality. As expected, the call to the Equals(BigInteger) method shows that they are unequal. However, the conversion of the larger BigInteger value back to a Single succeeds, although the BigInteger value now exceeds Single.MaxValue.

' Increase a BigInteger so it exceeds Single.MaxValue.
Dim number1 As BigInteger = CType(Single.MaxValue, BigInteger)
Dim number2 As BigInteger = number1
number2 = number2 + 9.999E+30
' Compare the BigInteger values for equality.
outputBlock.Text += String.Format("BigIntegers equal: {0}", number2.Equals(number1)) & vbCrLf

' Convert the BigInteger to a Single.
Dim sng As Single = CType(number2, Single)

' Display the two values.
outputBlock.Text += String.Format("BigInteger: {0}", number2) & vbCrLf
outputBlock.Text += String.Format("Single:     {0}", sng) & vbCrLf
' The example displays the following output:
'       BigIntegers equal: False
'       BigInteger: 3.4028235663752885981170396038E+38
'       Single:     3.402823E+38
// Increase a BigInteger so it exceeds Single.MaxValue.
BigInteger number1 = (BigInteger)Single.MaxValue;
BigInteger number2 = number1;
number2 = number2 + (BigInteger)9.999e30;
// Compare the BigInteger values for equality.
outputBlock.Text += String.Format("BigIntegers equal: {0}", number2.Equals(number1)) + "\n";

// Convert the BigInteger to a Single.
float sng = (float)number2;

// Display the two values.
outputBlock.Text += String.Format("BigInteger: {0}", number2) + "\n";
outputBlock.Text += String.Format("Single:     {0}", sng) + "\n";
// The example displays the following output:
//       BigIntegers equal: False
//       BigInteger: 3.4028235663752885981170396038E+38
//       Single:     3.402823E+38

Examples

The following example illustrates the conversion of BigInteger values to Single values.

Version Information

Silverlight

Supported in: 5, 4

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.