本文介绍了格式说明符%一个在C的printf()的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!

问题描述

我读C语言的书,它说%F,%E,%G,%A 是用于浮printf的字符双击数据类型。目前,我能理解%F,%E,%G 完全

I am reading a C language book, it said %f, %e, %g, %a were printf chars used for float and double data types. Currently I can understand %f, %e, %g completely.

当我需要用%A 打印浮动双击类型的数据?

When do I need use %a to print float and double type data ?

能否请你告诉我一个例子。

Can you please show me an example.

推荐答案

%A 格式化说明在C99是新的。它打印十六进制形式的浮点数。这是不是你会使用present号码的用户,但它是非常方便的在引擎罩/技术的使用案例。

The %a formatting specifier is new in C99. It prints the floating-point number in hexadecimal form. This is not something you would use to present numbers to users, but it's very handy for under-the-hood/technical use cases.

作为一个例子,这个code:

As an example, this code:

printf("pi=%a\n", 3.14);

打印:

pi=0x1.91eb86p+1

在评论中链接的优秀的文章解释说,这应该读1.91EB86 * 2 (也就是 p 幂的两个浮点数字提高到的)。在这种情况下,1.91EB86 是1.5700000524520874 。乘以这个2 ,你会得到3.140000104904175

The excellent article linked in the comments explains that this should be read "1.91EB86 * 2" (that is, the p is for power-of-two the floating-point number is raised to). In this case, "1.91EB86" is "1.5700000524520874". Multiply this by the "2", and you get "3.140000104904175".

请注意,这也有preserving的有用的属性precision的所有位,和presenting他们在一个可靠的方法。

Note that this also has the useful property of preserving all bits of precision, and presenting them in a robust way.

这篇关于格式说明符%一个在C的printf()的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持!

08-01 08:59