float (C# Reference)
The float keyword denotes a simple type that stores 32-bit floating-point values. The following table shows the precision and approximate range for the float type.
| Type | Approximate range | Precision | .NET Framework type |
|---|---|---|---|
float |
±1.5 × 10−45 to ±3.4 × 1038 |
7 digits |
Literals
By default, a real numeric literal on the right-hand side of the assignment operator is treated as double. Therefore, to initialize a float variable, use the suffix f or F, like this:
float x = 3.5F;
If you do not use the suffix in the previous declaration, you will get a compilation error because you are attempting to store a double value into a float variable.
Conversions
You can mix numeric integral types and floating-point types in an expression. In this case, the integral types are converted to floating-point types. The evaluation of the expression is performed according to the following rules:
If one of the floating-point types is double, the expression evaluates to double or bool in the case of relational or Boolean expressions.
If there is no double type in the expression, the expression evaluates to float or bool in the case of relational or Boolean expressions.
A floating-point expression can contain the following sets of values:
Positive and negative zero
Positive and negative infinity
Not-a-Number value (NaN)
The finite set of nonzero values
For more information on these values, refer to IEEE Standard for Binary Floating-Point Arithmetic, available on the Web site https://www.ieee.org/.
Example
In the following example, an int, a short, and a float are included in a mathematical expression giving a float result. Notice that there is no double in the expression.
// keyword_float.cs
// Mixing types in expressions
using System;
class MixedTypes
{
static void Main()
{
int x = 3;
float y = 4.5f;
short z = 5;
Console.WriteLine("The result is {0}", x * y / z);
}
}
Output
The result is 2.7
C# Language Specification
For more information, see the following sections in the C# Language Specification:
4.1.6 Floating Point Types
6.2.1 Explicit Numeric Conversions
See Also
Reference
C# Keywords
Integral Types Table (C# Reference)
Built-In Types Table (C# Reference)
Implicit Numeric Conversions Table (C# Reference)
Explicit Numeric Conversions Table (C# Reference)
Single Structure