[RESOLVED] "Single" for single precision floating point number

As the title, ‘Single’ holds a single decimal number? Or the result holds a single decimal value? Or anything else?

Ok, just look at the following code fragment.

Code:

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Single p = 225.2F;
Single q = 12.54F;
Single r = p / q;

Console.WriteLine(r);

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Output is 17.95853, and I’ve no idea what’s happened there. Where the single precision is?

Check on MSDN and fail. Please help me. How can I use it?

I have to say, you mustn't have looked very far. This is from the MSDN help topic for the Single structure:

Quote:

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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.

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as is this:

Quote:

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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.

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Here are the equivalent quotes from the MSDN help topic for the Double structure:

Quote:

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The Double value type represents a double-precision 64-bit number with values ranging from negative 1.79769313486232e308 to positive 1.79769313486232e308, as well as positive or negative zero, PositiveInfinity, NegativeInfinity, and Not-a-Number (NaN).

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

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Quote:

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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 Double value contains 15 decimal digits of precision, although a maximum of 17 digits is maintained internally.

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Thanks,

I got the same kind of explanation there in MSDN.

Quote:

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Originally Posted by jmcilhinney

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.

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As this says, single just approximating the 7^th decimal point in floating-point numbers and the 15^th decimal point in double type number.

Am I correct.