Why would you ever want to have an array on the heap?

Why would you ever want to have an array on the heap? My professor gave us two reasons: To pass the array to functions, instead of passing a copy So that the array outlives the scope Can't these both instead by solved by: Passing a pointer to an array on the stack Returning the value of the array instead of the array itself (ie use the copy constructor) Could someone give me an e

为什么你会想要在堆上有一个数组?

为什么你会想要在堆上有一个数组? 我的教授给了我们两个理由: 将数组传递给函数,而不是传递副本 这样数组就超出了范围 不能这些,而是​​通过解决: 将指针传递给堆栈上的数组 返回数组的值而不是数组本身(即使用复制构造函数) 有人能给我一个例子,说明堆中的数组必须被使用吗? 堆中的数组用于超出函数的范围。 将指针传递给堆栈上的数组仅适用于以后在上一个(上层)调用方中不想使用它的情况。 你不能

Where in memory are string literals ? stack / heap?

Possible Duplicate: C String literals: Where do they go? As far as I know, generally, pointer have to be allocated by malloc(), and will be allocated to heap, then unallocated by free(); and non pointer(int,char,float,etc..) will be allocated automatically to stack, and unallocated as long as the function go to return but, from following code : #include <stdio.h> int main() {

内存中的字符串文字是什么? 堆栈/堆?

可能重复: C字符串文字:他们去哪里? 我所知道的, 通常,指针必须由malloc()分配,并将分配给堆,然后由free()分配。 和 非指针(int,char,float等)将自动分配给堆栈,并且只要函数返回,就不会分配 但是,从以下代码: #include <stdio.h> int main() { char *a; a = "tesaja"; return 0; } 其中,将a分配给? 堆栈还是堆? 字符串文字将在数据段中分配。 指向它的指针a将被分配到堆栈中

Why is the use of alloca() not considered good practice?

alloca() allocates memory from Stack rather than heap which is case in malloc() . So, when I return from the routine the memory is freed. So, actually this solves my problem of freeing up of dynamically allocated memory. Freeing of memory allocated through malloc() is a major headache and if somehow missed leads to all sorts memory problems. Why is the use of alloca() discouraged in spite of

为什么使用alloca()不被认为是好的做法?

alloca()从堆栈中分配内存,而不是malloc()堆。 所以,当我从例程返回时,内存被释放。 所以,实际上这解决了我释放动态分配内存的问题。 释放通过malloc()分配的内存是一个非常头痛的问题,如果不知何故错过了会导致各种内存问题。 尽管有上述特征,为什么使用alloca()不鼓励? 答案就在man页(至少在Linux上): 返回值alloca()函数返回一个指向分配空间开始的指针。 如果分配导致堆栈溢出,则程序行为未定义。

Is there any limit on stack memory?

I was going through one of the threads. A program crashed because it had declared an array of 10^6 locally inside a function. Reason being given was memory allocation failure on stack leads to crash. when same array was declared globally, it worked well.(memory on heap saved it). Now for the moment, let us suppose, stack grows downward and heap upwards. We have: ---STACK--- ---------

堆栈内存是否有限制?

我正在通过其中一个主题。 程序崩溃是因为它在一个函数内部本地声明了一个10 ^ 6的数组。 给出的原因是堆栈上的内存分配失败导致崩溃。 当全局声明相同的数组时,它运行良好(堆上的内存保存了它)。 现在,我们假设,堆栈向下堆积并向上堆积。 我们有: --- STACK --- ------------------- - -堆 - - 现在,我相信如果在堆栈上分配失败,它也必须在堆上失败。 所以我的问题是:堆栈大小是否有限制? (

Measure CPU and RAM Usage of Child Process

I have the following process: public void Run() { ProcessStartInfo serverPInfo = new ProcessStartInfo("javaw", "-jar -Xms1024M -Xmx1024M "C:\Users\David\Documents\Visual Studio 2012\Projects\ConsoleApplication8\Debug\craftbukkit.jar" -o true -nojline"); serverPInfo.RedirectStandardInput = true; serverPInfo.RedirectStandardOutput = true; se

测量子进程的CPU和RAM使用情况

我有以下过程: public void Run() { ProcessStartInfo serverPInfo = new ProcessStartInfo("javaw", "-jar -Xms1024M -Xmx1024M "C:\Users\David\Documents\Visual Studio 2012\Projects\ConsoleApplication8\Debug\craftbukkit.jar" -o true -nojline"); serverPInfo.RedirectStandardInput = true; serverPInfo.RedirectStandardOutput = true; serverPInfo.Redir

How do I determine the size of my array in C?

How do I determine the size of my array in C? That is, the number of elements the array can hold? Executive summary: int a[17]; size_t n = sizeof(a)/sizeof(a[0]); To determine the size of your array in bytes, you can use the sizeof operator: int a[17]; size_t n = sizeof(a); On my computer, ints are 4 bytes long, so n is 68. To determine the number of elements in the array, we can divide

我如何确定C中数组的大小?

我如何确定C中数组的大小? 也就是说,数组可以容纳的元素数量? 执行摘要: int a[17]; size_t n = sizeof(a)/sizeof(a[0]); 要以字节为单位确定数组的大小,可以使用sizeof运算符: int a[17]; size_t n = sizeof(a); 在我的电脑上,整数是4个字节,所以n是68。 为了确定数组中元素的数量,我们可以将数组的总大小除以数组元素的大小。 你可以用类型来做到这一点,就像这样: int a[17]; size_t n = sizeof(a) / si

How to get the size of available system memory?

Is it possible to get the size of system available memory in C#.NET? if yes how? Use Microsoft.VisualBasic.Devices.ComputerInfo.TotalPhysicalMemory . Right-click your project, Add Reference, select Microsoft.VisualBasic . This answer is based on Hans Passant's. The required property is AvailablePhysicalMemory actually. and it (and TotalPhysicalMemory and others) are instance variable

如何获得可用系统内存的大小?

是否有可能在C#.NET中获得系统可用内存的大小? 如果是的话如何? 使用Microsoft.VisualBasic.Devices.ComputerInfo.TotalPhysicalMemory 。 右键单击您的项目,添加引用,选择Microsoft.VisualBasic 。 这个答案是基于Hans Passant的。 实际需要的属性是AvailablePhysicalMemory。 它(和TotalPhysicalMemory等)是实例变量,所以它应该是 new ComputerInfo().AvailablePhysicalMemory 它用C#工作,但我想知道为什

What's the difference between an array and a pointer in C exactly?

This question may sound stupid but I'm not really sure about it. I mean, what's the difference between: char* line = (char*) malloc(MAX_LINE_LEN); and char line[MAX_LINE_LEN]; exactly? I know the former is a pointer and the latter is an array, but how can the system tell the difference? How is the memory allocated/stored? Also, why can you delete the memory occupied by line when

C中的数组和指针之间有什么区别?

这个问题可能听起来很愚蠢,但我并不确定。 我的意思是,有什么区别: char* line = (char*) malloc(MAX_LINE_LEN); 和 char line[MAX_LINE_LEN]; 究竟? 我知道前者是一个指针,后者是一个数组,但系统如何区分这个差异? 如何分配/存储内存? 另外,为什么当它被声明为一个指针时删除line占用的内存,而不是当它是一个数组? 我认为一个数组存储在其他地方,当超出范围时,系统会自动释放它的内存,这在处理指针时不

XNode.DeepEquals unexpectedly returns false

Using XNode.DeepEquals() to compare xml elements, it unexpectedly returns false on two xml documents that I think should be equivalent. Example var xmlFromString = XDocument.Parse("<someXml xmlns="someNamespace"/>"); var xmlDirect = new XDocument(new XElement( XNamespace.Get("someNamespace") + "someXml")); Console.WriteLine(xmlFromString.ToString()); Console.WriteLine(xmlDirect.ToStri

XNode.DeepEquals意外地返回false

使用XNode.DeepEquals()来比较xml元素,它意外地在我认为应该是等价的两个xml文档上返回false 。 例 var xmlFromString = XDocument.Parse("<someXml xmlns="someNamespace"/>"); var xmlDirect = new XDocument(new XElement( XNamespace.Get("someNamespace") + "someXml")); Console.WriteLine(xmlFromString.ToString()); Console.WriteLine(xmlDirect.ToString()); Console.WriteLine(XNode.DeepEquals(xmlFromS

Is it possible to find the edge of a "spotty" region in emgucv?

I have an image that looks like this: and I want to find the edges of the dark part so like this (the red lines are what I am looking for): I have tried a few approaches and none have worked so I am hoping there is an emgu guru out there willing to help me... Approach 1 Convert the image to grayscale Remove noise and invert Remove anything that is not really bright Get the canny and

是否有可能找到emgucv中“斑点”区域的边缘?

我有一个像这样的图像: 我想找到这样的黑暗部分的边缘(红线是我正在寻找的): 我尝试了一些方法,但都没有工作,所以我希望有一个emgu教练愿意帮助我... 方法1 将图像转换为灰度 消除噪音并翻转 删除任何不太亮的东西 获取canny和多边形 代码(我知道我应该正确地处理事情,但我保持代码简短): var orig = new Image<Bgr, byte>(inFile); var contours = orig .Convert<Gray, byte>()