printf（"％f"）问题 [英] printf("%f") question

问题描述

如果我们想用printf打印浮点数，则打印一个printf（％f，x）;

足够，或者像printf一样需要强制转换（％f，（double）x）; ？

解决方案

澄清：问题是关于C90 / C95。


Ioannis Vranos写道：

如果我们想用printf打印一个浮点数，一个printf（％f，x）;

足够，或者像printf一样需要强制转换（％f，（double）x）; ？

On Sun，2008年3月2日15:16:11 +0200，Ioannis Vranos写道：

如果我们想用printf打印一个浮点数，则打印一个printf（％f，x）;

足够，或者像printf一样需要强制转换（％f，（double）x）; ？

函数的变量参数的任何浮点参数将被提升为double的
。两者都很好。

Harald van Dijk写道：

函数变量参数的任何浮点参数将

晋升为双倍。两者都很好。

我认为以下内容也是正确的：


signed char sc = 15;

unsigned char uc = 130;


printf（"％d\t％hu \t％u"，sc，uc，uc）;

If we want to print a float with printf, a printf("%f", x); is
sufficient, or a cast is needed like in printf("%f", (double)x); ?

解决方案

Clarification: The question is about C90/C95.

Ioannis Vranos wrote:

If we want to print a float with printf, a printf("%f", x); is
sufficient, or a cast is needed like in printf("%f", (double)x); ?

On Sun, 02 Mar 2008 15:16:11 +0200, Ioannis Vranos wrote:

If we want to print a float with printf, a printf("%f", x); is
sufficient, or a cast is needed like in printf("%f", (double)x); ?

Any float argument to the variable arguments of a function will be
promoted to double. Both are fine.

Harald van Dijk wrote:

Any float argument to the variable arguments of a function will be
promoted to double. Both are fine.

I suppose the following are also correct:

signed char sc= 15;
unsigned char uc= 130;

printf("%d\t%hu\t%u", sc, uc, uc);

这篇关于printf（"％f"）问题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IT屋！