Possible Duplicates: Do I cast the result of malloc? Should I explicitly cast malloc()'s return value? Hello, gcc 4.4.4 c89 Normally I don't cast the return result from a malloc call. int *int_ptr = NULL; int_ptr = malloc(sizeof(int)); However, I have read on here, that if you cast it can hide errors. How does it hide errors if you explicitly cast to an int? int_ptr = (int*)
可能重复: 我输入malloc的结果吗? 我应该明确地施放malloc()的返回值吗? 你好, gcc 4.4.4 c89 通常我不会从malloc调用返回结果。 int *int_ptr = NULL; int_ptr = malloc(sizeof(int)); 不过,我在这里看过,如果你施放它可以隐藏错误。 如果你显式转换为int,它如何隐藏错误? int_ptr = (int*)malloc(sizeof(int)); 另外,我正在阅读一本关于编程的书,其中指出从包含malloc调用的void指针投射出来的编程
The following code snippet (correctly) gives a warning in C and an error in C++ (using gcc & g++ respectively, tested with versions 3.4.5 and 4.2.1; MSVC does not seem to care): char **a; const char** b = a; I can understand and accept this. The C++ solution to this problem is to change b to be a const char * const *, which disallows reassignment of the pointers and prevents you from circ
下面的代码片段(正确地)给出了C中的警告和C ++中的错误(分别使用gcc&g ++,在版本3.4.5和4.2.1中进行了测试; MSVC似乎并不在意): char **a; const char** b = a; 我可以理解并接受这一点。 解决此问题的C ++解决方案是将b更改为const char * const *,它禁止重新分配指针,并且阻止您规避常量正确性(C ++ FAQ)。 char **a; const char* const* b = a; 但是,在纯C中,更正后的版本(使用const char * const *)仍
This question already has an answer here: Do I cast the result of malloc? 27 answers C中的void指针可以分配给任何指针而不需要显式强制转换。 If you like the "don't repeat yourself" mindset, it should be appealing that you don't need to repeat the type name from the declaration of the variable, in the malloc() call. Because, as folks have pointed out, you don't: pointers
这个问题在这里已经有了答案: 我输入malloc的结果吗? 27个答案 C中的void指针可以分配给任何指针而不需要显式强制转换。 如果你喜欢“不要重复自己”的思维方式,那么应该有吸引力,你不需要在malloc()调用中重复变量声明中的类型名称。 因为,正如人们已经指出的那样,你不需要:除了函数指针之外,指针可以毫无损失地转换成void *和void * 。 另外,在该说明中,您不需要重复使用sizeof 。 你的第二个例子,当分配一
I have some C code. What it does is simple, get some array from io, then sort it. #include <stdio.h> #include <stdlib.h> #define ARRAY_MAX 2000000 int main(void) { int my_array[ARRAY_MAX]; int w[ARRAY_MAX]; int count = 0; while (count < ARRAY_MAX && 1 == scanf("%d", &my_array[count])) { count++; } merge_sort(my_array, w, count);
我有一些C代码。 它做的很简单,从io获得一些数组,然后对其进行分类。 #include <stdio.h> #include <stdlib.h> #define ARRAY_MAX 2000000 int main(void) { int my_array[ARRAY_MAX]; int w[ARRAY_MAX]; int count = 0; while (count < ARRAY_MAX && 1 == scanf("%d", &my_array[count])) { count++; } merge_sort(my_array, w, count); return EXIT_SU
On Linux I have a code that use a array declared inside the main function with a sixe of 2MB + 1 byte #include <stdio.h> #include <stdlib.h> #define MAX_DATA (2097152) /* 2MB */ int main(int argc, char *argv[]) { /* Reserve 1 byte for null termination */ char data[MAX_DATA + 1]; printf("Byen"); return 0; } When I compiled on Linux with gcc I run it without any p
在Linux上,我有一个代码,它使用在主函数内部声明的数组,并且具有2MB + 1字节的六位数 #include <stdio.h> #include <stdlib.h> #define MAX_DATA (2097152) /* 2MB */ int main(int argc, char *argv[]) { /* Reserve 1 byte for null termination */ char data[MAX_DATA + 1]; printf("Byen"); return 0; } 当我用gcc编译Linux时,我运行它没有任何问题。 但在Windows上,我得到一个运
By considering that the memory is divided into four segments: data, heap, stack, and code, where do global variables, static variables, constant data types, local variables (defined and declared in functions), variables (in main function), pointers, and dynamically allocated space (using malloc and calloc) get stored in memory? I think they would be allocated as follows: Global variables ----
通过考虑内存分为四个部分:数据,堆,堆栈和代码,全局变量,静态变量,常量数据类型,局部变量(在函数中定义和声明),变量(在主函数中),指针,并动态分配空间(使用malloc和calloc)获取存储在内存中? 我认为他们将被分配如下: 全局变量-------> 堆 (静态和全局变量都存储在堆中,根据Robert Lafore的书面向C ++编程 静态变量-------> 堆 常量数据类型----->代码 局部变量(在函数中声明和定义)--
I have a label with AutoEllipsis = true and TextAlign = ContentAlignment.MiddleLeft . When I enter a text that is not extending the label width, the text is vertically aligned to the middle of the label. However, when the text extends the label width the text is not aligned to the middle, but top aligned instead. Why is it behaving this way, and is there a way to keep the text vertically cen
我有一个AutoEllipsis = true和TextAlign = ContentAlignment.MiddleLeft的标签。 当我输入的文本不是扩展标签宽度时,文本垂直对齐标签的中间。 但是,当文本扩展标签宽度时,文本不会与中间对齐,而是顶部对齐。 为什么它会这样做,并且有没有办法让文本垂直居中对齐? 我看到了。 这看起来像是底层winapi,DrawTextEx()中的一个限制。 它没有得到Label类的很多帮助,它没有打开DT_SINGLELINE选项(又名TextFormatF
I'm using Dapper and I have classes like this: public class Article{ public int Id { get; set; } public string Description{get;set;} public Group Group { get; set; } public List<Barcode> Barcode {get;set;} ... } public class Group{ public int Id { get; set; } public string Description {get;set;} } public class Barcode{ public int Id { get; set; } public str
我正在使用Dapper,并且我有这样的类: public class Article{ public int Id { get; set; } public string Description{get;set;} public Group Group { get; set; } public List<Barcode> Barcode {get;set;} ... } public class Group{ public int Id { get; set; } public string Description {get;set;} } public class Barcode{ public int Id { get; set; } public string Code{get;s
I have a list of complex objects ie class MyObject { public bool selected; public int id; public string name; } List<MyObject> theObjects = functionThatSelectsObjectsFromContainer(); And I have a list from another source that just give me int ids that are in the list of objects List<int> idList = functionThatReturnsListOfIds(); Now for each of the items in the idList
我有一个复杂的对象列表即 class MyObject { public bool selected; public int id; public string name; } List<MyObject> theObjects = functionThatSelectsObjectsFromContainer(); 我有一个来自另一个来源的列表,只是给了我对象列表中的int id List<int> idList = functionThatReturnsListOfIds(); 现在对于idList中的每个项目,我想将selected属性设置为true。 我知道我可以设置一个列表的
This question already has an answer here: IEnumerable vs List - What to Use? How do they work? 9 answers One important difference between IEnumerable and List (besides one being an interface and the other being a concrete class) is that IEnumerable is read-only and List is not. So if you need the ability to make permanent changes of any kind to your collection (add & remove), you'
这个问题在这里已经有了答案: IEnumerable vs List - 使用什么? 他们如何工作? 9个答案 IEnumerable和List之间的一个重要区别(除了一个是接口,另一个是具体类),IEnumerable是只读的,List不是。 因此,如果您需要对您的收藏进行任何形式的永久性更改(添加和删除),您需要列表。 如果您只需要阅读,排序和/或筛选您的集合,那么IEnumerable就足够了。 所以在你的实际例子中,如果你想一次添加四个字符串,你