在C ++中使用malloc？ [英] Using malloc in C++?
问题描述
我在Bjarne Stroustrup中读过，使用malloc和free应该在C ++中避免使用
，因为它们处理的是未初始化的内存，而一个
应该使用new和delete。
但为什么会出现问题呢？我不明白为什么使用malloc代替新的
不能给出相同的结果。
I have read in Bjarne Stroustrup that using malloc and free should be
avoided in C++ because they deal with uninitialized memory and one
should instead use new and delete.
But why is that a problem? I cannot see why using malloc instead of new
does not give the same result.
推荐答案
" desktop" < ff*@sss.com写信息
news：f4 ********** @ news.net.uni-c.dk ...
"desktop" <ff*@sss.comwrote in message
news:f4**********@news.net.uni-c.dk...
>我在Bjarne Stroustrup中读过，在C ++中应该避免使用malloc和free，因为它们处理未初始化的内存而应该使用new和delete 。
但为什么会出现问题呢？我不明白为什么使用malloc代替新的
不会给出相同的结果。
>I have read in Bjarne Stroustrup that using malloc and free should be
avoided in C++ because they deal with uninitialized memory and one should
instead use new and delete.
But why is that a problem? I cannot see why using malloc instead of new
does not give the same result.
（未经测试的代码）
class Foo
{
int MyInt;
std :: string MyString;
};
int main（）
{
Foo * Bar = new Foo;
Foo * Screwed = malloc（sizeof（Foo））;
}
New将调用std :: string的构造函数。 malloc不会。
(Untested code)
class Foo
{
int MyInt;
std::string MyString;
};
int main()
{
Foo* Bar = new Foo;
Foo* Screwed = malloc( sizeof( Foo ) );
}
New will call the constructor for the std::string. malloc won''t.
desktop写道：
desktop wrote:
我有在Bjarne Stroustrup中读到使用malloc和free应该在C ++中避免使用
，因为它们处理的是未初始化的内存，而一个
应该使用new和delete。
但为什么会出现问题呢？
I have read in Bjarne Stroustrup that using malloc and free should be
avoided in C++ because they deal with uninitialized memory and one
should instead use new and delete.
But why is that a problem?
当你处理C ++中的对象分配问题时，
new不仅会分配内存而且还会带来构造函数。
The problem comes when you deal with object allocation, in C++, where
new not only allocates memory but also takes the constructor in hand.
>我看不出为什么使用malloc代替新的
不能给出相同的结果。
>I cannot see why using malloc instead of new
does not give the same result.
为了更好地理解，请通过以下链接：
http://wiki.answers.com/Q/What_is_th...er_than_syntax
问候，
ar
有些事情已知且事情未知，介于两者之间。
For better understanding go through this link :
http://wiki.answers.com/Q/What_is_th...er_than_syntax
Regards,
ar
"There are things known and things unknown, in between are The Doors."
desktop写道：
desktop wrote:
我在Bjarne Stroustrup中读过，使用malloc和free应该在C ++中避免使用
，因为它们处理的是未初始化的内存和一个/>
应改为使用new和delete。
但为什么会出现问题呢？我不明白为什么使用malloc代替新的
不会给出相同的结果。
I have read in Bjarne Stroustrup that using malloc and free should be
avoided in C++ because they deal with uninitialized memory and one
should instead use new and delete.
But why is that a problem? I cannot see why using malloc instead of new
does not give the same result.
对于一桶字节或C样式结构，使用malloc / free或
new / delete几乎没有区别。对于带有构造函数的对象
和/或析构函数，你必须使用new / delete，所以你也可以使用
对所有的分配都一样。
-
Ian Collins。
For a bucket of bytes or a C style struct, using malloc/free or
new/delete makes little or no difference. For objects with constructors
and/or destructors you have to use new/delete, so you may as well use
the same for all allocations.
--
Ian Collins.
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