Codeblocks的gcc编译器出错，double型数据输出出错。

[qq_29918899]

前几天让我的CB支持C11的时候，不知道编译器设置那里手贱删了什么东西或者是设置了哪里。

后面使用的时候，遇到double型数据经常会出错，而同样的代码在DEV C就没错，哪位大神帮我看看怎么修好。

[qq_29918899]

引用 1 楼 hnwyllmm 的回复:

这么奇葩的问题，还原一下默认配置重来一遍

问题是我不知道怎么还原设置啊，我把软件卸载了，清除了注册表，删除了根目录文件，重装还是这样啊。

[qq_29918899]

引用 2 楼 qq423399099 的回复:

用%f输出double就行了 在C89中明确说明 printf("%lf", (doube)d); 的结果是未定义的。 An optional h specifying that a following d, i, o, u, x, or X conversion specifier applies to a short int or unsigned short int argument (the argument will have been promoted according to the integral promotions, and its value shall be converted to short int or unsigned short int before printing); an optional h specifying that a following n conversion specifier applies to a pointer to a short int argument; an optional l (ell) specifying that a following d, i, o, u, x, or X conversion specifier applies to a long int or unsigned long int argument; an optional l specifying that a following n conversion specifier applies to a pointer to a long int argument; or an optional L specifying that a following e, E, f, g, or G conversion specifier applies to a long double argument. If an h, l, or L appears with any other conversion specifier, the behavior is undefined. C99中则说 printf("%lf", (doube)d); 相当于 printf("%f", (doube)d); l (ell) Specifies that a following d, i, o, u, x, or X conversion specifier applies to a long int or unsigned long int argument; that a following n conversion specifier applies to a pointer to a long int argument; that a following c conversion specifier applies to a wint_t argument; that a following s conversion specifier applies to a pointer to a wchar_t argument; or has no effect on a following a, A, e, E, f, F, g, or G conversion specifier.

谢谢！我改成%f就能正确输出了，所以应该是我把C99的选项给删了？在用C89？所以只用把C99或者C11调回来就行了？

[小灸舞]

引用 5 楼 qq_29918899 的回复:

[quote=引用 2 楼 qq423399099 的回复:] 用%f输出double就行了 在C89中明确说明 printf("%lf", (doube)d); 的结果是未定义的。 An optional h specifying that a following d, i, o, u, x, or X conversion specifier applies to a short int or unsigned short int argument (the argument will have been promoted according to the integral promotions, and its value shall be converted to short int or unsigned short int before printing); an optional h specifying that a following n conversion specifier applies to a pointer to a short int argument; an optional l (ell) specifying that a following d, i, o, u, x, or X conversion specifier applies to a long int or unsigned long int argument; an optional l specifying that a following n conversion specifier applies to a pointer to a long int argument; or an optional L specifying that a following e, E, f, g, or G conversion specifier applies to a long double argument. If an h, l, or L appears with any other conversion specifier, the behavior is undefined. C99中则说 printf("%lf", (doube)d); 相当于 printf("%f", (doube)d); l (ell) Specifies that a following d, i, o, u, x, or X conversion specifier applies to a long int or unsigned long int argument; that a following n conversion specifier applies to a pointer to a long int argument; that a following c conversion specifier applies to a wint_t argument; that a following s conversion specifier applies to a pointer to a wchar_t argument; or has no effect on a following a, A, e, E, f, F, g, or G conversion specifier.

谢谢！我改成%f就能正确输出了，所以应该是我把C99的选项给删了？在用C89？所以只用把C99或者C11调回来就行了？[/quote] 一试便知

[qq_29918899]

引用 6 楼 qq423399099 的回复:

[quote=引用 5 楼 qq_29918899 的回复:] [quote=引用 2 楼 qq423399099 的回复:] 用%f输出double就行了 在C89中明确说明 printf("%lf", (doube)d); 的结果是未定义的。 An optional h specifying that a following d, i, o, u, x, or X conversion specifier applies to a short int or unsigned short int argument (the argument will have been promoted according to the integral promotions, and its value shall be converted to short int or unsigned short int before printing); an optional h specifying that a following n conversion specifier applies to a pointer to a short int argument; an optional l (ell) specifying that a following d, i, o, u, x, or X conversion specifier applies to a long int or unsigned long int argument; an optional l specifying that a following n conversion specifier applies to a pointer to a long int argument; or an optional L specifying that a following e, E, f, g, or G conversion specifier applies to a long double argument. If an h, l, or L appears with any other conversion specifier, the behavior is undefined. C99中则说 printf("%lf", (doube)d); 相当于 printf("%f", (doube)d); l (ell) Specifies that a following d, i, o, u, x, or X conversion specifier applies to a long int or unsigned long int argument; that a following n conversion specifier applies to a pointer to a long int argument; that a following c conversion specifier applies to a wint_t argument; that a following s conversion specifier applies to a pointer to a wchar_t argument; or has no effect on a following a, A, e, E, f, F, g, or G conversion specifier.

谢谢！我改成%f就能正确输出了，所以应该是我把C99的选项给删了？在用C89？所以只用把C99或者C11调回来就行了？[/quote] 一试便知[/quote] 现在的问题是，我好像调不回C99模式了，我添加-std=c99，一点反应都没有，还是一样的错误啊。

[qq_29918899]

会出现这样的提示。

[小灸舞]

试验证明：无论是double %lf 还是 float %f, 无论是否设置-std=c99, 结果都没有什么不同！

[赵4老师]

%lg 笑而不语

[羽飞]

手动执行GCC命令编译看结果试试

[ynsenyu]

当初满世界搜索%zu

[羽飞]

这么奇葩的问题，还原一下默认配置重来一遍

[小灸舞]

用%f输出double就行了 在C89中明确说明 printf("%lf", (doube)d); 的结果是未定义的。 An optional h specifying that a following d, i, o, u, x, or X conversion specifier applies to a short int or unsigned short int argument (the argument will have been promoted according to the integral promotions, and its value shall be converted to short int or unsigned short int before printing); an optional h specifying that a following n conversion specifier applies to a pointer to a short int argument; an optional l (ell) specifying that a following d, i, o, u, x, or X conversion specifier applies to a long int or unsigned long int argument; an optional l specifying that a following n conversion specifier applies to a pointer to a long int argument; or an optional L specifying that a following e, E, f, g, or G conversion specifier applies to a long double argument. If an h, l, or L appears with any other conversion specifier, the behavior is undefined. C99中则说 printf("%lf", (doube)d); 相当于 printf("%f", (doube)d); l (ell) Specifies that a following d, i, o, u, x, or X conversion specifier applies to a long int or unsigned long int argument; that a following n conversion specifier applies to a pointer to a long int argument; that a following c conversion specifier applies to a wint_t argument; that a following s conversion specifier applies to a pointer to a wchar_t argument; or has no effect on a following a, A, e, E, f, F, g, or G conversion specifier.

[tiankong_bear]

2楼正解！！