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c语言字符串常量内容是否可以通过指针修改 - C/C++ - 清泛网 - 专注C/C++及内核技术
...是:不行。尝试修改的话,运行时程序会崩溃。int main(){ char str1[40]="hello world!"; char *str1="hello world!"...答案是:不行。尝试修改的话,运行时程序会崩溃。
int main()
{
char str1[40]="hello world!"; //char *str1="hello world!";
str1[4]...
c/c++如何判断指针无效?如NULL,0xcccccccc,0xfeeefeee,野指针等 - C/C++ -...
...何判断指针是否有效呢?
AfxIsValidAddress
// Allocate a 5 character array, which should have a valid memory address.
char* arr = new char[5];
// Create a null pointer, which should be an invalid memory address.
char* null = (char*)0x0;
ASSERT(AfxIsValidAddress(arr, 5));
ASSE...
C/C++获取Windows的CPU、内存、硬盘使用率 - C/C++ - 清泛网 - 专注C/C++及内核技术
...icalDriveStrings()函数获取所有驱动器字符串信息长度。
char* DStr = new char[DSLength];//用获取的长度在堆区创建一个c风格的字符串数组
GetLogicalDriveStrings(DSLength, (LPTSTR)DStr);
//通过GetLogicalDriveStrings将字符串信息复制到堆区数...
【解决】munmap_chunk(): invalid pointer - C/C++ - 清泛网 - 专注C/C++及内核技术
...指针被覆盖掉了,然后delete free就会报这个错误。例如:char* word = (char*)malloc(10);word = "abc"; 应使用 strcpy(word, "abc");free(word) 原因:new/malloc出来的指针被覆盖掉了,然后delete/free就会报这个错误。
例如:
char* word = (char*)malloc(1...
How to remove last n characters from every element in the R vector
..., and I could not find a simple example online of how to remove the last n characters from every element of a vector (array?)
...
Clean code to printf size_t in C++ (or: Nearest equivalent of C99's %z in C++)
...retty one..
template< class T >
struct GetPrintfID
{
static const char* id;
};
template< class T >
const char* GetPrintfID< T >::id = "%u";
template<>
struct GetPrintfID< unsigned long long > //or whatever the 64bit unsigned is called..
{
static const char* id;
...
Difference between a Structure and a Union
...re that value.
union foo {
int a; // can't use both a and b at once
char b;
} foo;
struct bar {
int a; // can use both a and b simultaneously
char b;
} bar;
union foo x;
x.a = 3; // OK
x.b = 'c'; // NO! this affects the value of x.a!
struct bar y;
y.a = 3; // OK
y.b = 'c'; // OK
ed...
What's the opposite of chr() in Ruby?
... pair of functions, chr() and ord() , which convert between numbers and character values. In some languages, ord() is called asc() .
...
Does delete on a pointer to a subclass call the base class destructor?
...n this will happen when the containing object is destroyed.
class A
{
char *someHeapMemory;
public:
A() : someHeapMemory(new char[1000]) {}
~A() { delete[] someHeapMemory; }
};
class B
{
A* APtr;
public:
B() : APtr(new A()) {}
~B() { delete APtr; }
};
class C
{
A Amemb...
Method Syntax in Objective-C
...ersonData) for setting some information about person:
void setPersonData( char* name, int age, float height ) {
and in Objective-C the method would be more descriptive (setPersonName:andAge:andHeight:), like
- (void) setPersonName: (char *)name andAge:(int)age andHeight:(float)height {
...
