程式語言C 不懂書上的意思

A float number is typically a 32-bit quantity,with at least six significant digits

and magnitude generally between about 10的負38次方 and 10的正38次方

我不懂為麼大小直範圍在 10的負38次方 和 10的正38次方

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    Mukesh_Singh_Nick...yahoo.com writes:

    What is meant by the "most significant digits" in the following

    statement?

    Don't bother with markup like this. Usenet news is a plain text

    medium. People sometimes use markers for humorous effect

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    your post with HTML or similar.

    With %g and %G, the precision modifier determines the maximum number

    of significant digits displayed.

    You say "most" at the top but the quote has "maximum" so I am i bit

    圖片參考:http://reference.itags.org/reference/pic/?url=/lib...

    about what is bothering you. The precision determines how

    much of number gets represented. Obviously only the most significant

    digits are used but you can say "no more than X digits". There may

    be other stuff printed, because %g might use scientific notation, but

    the precision limits the number of significant digits printed. The

    number you give is a maximum because fewer may be sufficient:

    4.0e30 using %.3g prints "4e+30"

    4.3e30 using %.1g prints "4e+30"

    4.3e30 using %.2g prints "4.1e+30"

    The statement appears here:

    http://www.cppreference.com/stdio/printf.html

    Look like a C++ reference. This may lead you astray if you are using

    it for C. Read the C FAQ instead: http://c-faq.com/

    Also, what do we mean by the magnitude of a floating point number?

    I understand that the magnitude of an integral is equal to its

    absolute value. However, I do not understand the meaning of the

    magnitude of a floating point.

    It usually means exactly the same -- the absolute value. It certainly

    does in the quote you cite from K&R:

    A float number is typically a 32-bit quantity, with at

    least six significant digits and magnitude generally between about

    10^(-38) and 10^(+38).

    Source: K & R, Page 9, Second Edition

    Ben.

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  • 1 decade ago

    可以來個中文嗎?

    看不太懂ㄝ

    解釋給我我問的最後一句^^

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