This question already has an answer here: Are there benefits of passing by pointer over passing by reference in C++? 6 answers C++ In C++, you can pass by reference, and you do that when you want modifications of the parameter to affect the argument which the caller passed in. That is, passing by reference represents an out or in/out parameter. You pass a pointer if the function wants a
这个问题在这里已经有了答案： 在C ++中通过引用传递指针会带来什么好处？ 6个答案 C ++ 在C ++中，你可以通过引用传递，而当你想要修改参数来影响调用者传入的参数时，你可以这样做。也就是说，通过引用传递代表out或in / out参数。 如果函数想要一个指针（显然），或者如果您想要表示一个可选的输出参数，则传递一个指针 - 因为引用总是必须绑定到某个对象，但指针可以为null。 通过相同的逻辑，如果函数实际需要双
Possible Duplicates: When pass-by-pointer is preferred to pass-by-reference in C++? Are there benefits of passing by pointer over passing by reference in C++? How to pass objects to functions in C++? Hi all, I'm working to develop a large object oriented c++ application framework as part of my chemical engineering graduate research. I find that many of my functions take pointers to
可能重复： 在C ++中，传递指针比传递引用更受欢迎？ 在C ++中通过引用传递指针会带来什么好处？ 如何将对象传递给C ++中的函数？ 大家好，我正在开发一个面向对象的大型c ++应用程序框架，作为我的化学工程研究生研究的一部分。 我发现我的许多函数都指向自定义对象或STL对象。 我发现在编写代码方面，这使得访问存储在其中的函数或变量更加困难。 除了简单之外，通过引用传递指针还是有优点/缺点吗？ 如果一个
Possible Duplicate: What are the differences between pointer variable and reference variable in C++? Are there benefits of passing by pointer over passing by reference in C++? In both cases, I achieved the result. So when is one preferred over the other? What are the reasons we use one over the other? #include <iostream> using namespace std; void swap(int* x, int* y) { int z =
可能重复： C ++中指针变量和引用变量之间有什么区别？ 在C ++中通过引用传递指针会带来什么好处？ 在这两种情况下，我都达到了结果。 那么什么时候比其他人更喜欢？ 我们之间使用一个的原因是什么？ #include <iostream> using namespace std; void swap(int* x, int* y) { int z = *x; *x=*y; *y=z; } void swap(int& x, int& y) { int z = x; x=y; y=z; } int main() { i
Possible Duplicates: pass by reference or pass by value? Pass by Reference / Value in C++ Im having trouble with the pass-by-value-result method. i understand pass by reference and pass by value but im not quite clear on pass-by-value result. How similar is it to pass by value(assuming it is similar)? here is the code #include <iostream> #include <string.h> using namespace
可能重复： 通过引用传递还是传递值？ 在C ++中通过引用/值传递 我在传递值结果方法中遇到了问题。 我明白通过参考和传递的价值，但我不太清楚通过价值的结果。 通过价值传递有多相似（假设它是相似的）？ 这里是代码 #include <iostream> #include <string.h> using namespace std; void swap(int a, int b) { int temp; temp = a; a = b; b = temp; } int main() { int value = 2;
Possible Duplicate: What's the difference between passing by reference vs. passing by value? I know that the title can represent many other answered questions, I believe that my very specific question wasn't answered in other threads (I have searched, sorry if it's a duplicate). To business: consider the next signatures: A: void MyFunction(long int x); B: void MyFunction(lo
可能重复： 传递引用与价值传递之间有什么区别？ 我知道标题可以代表很多其他回答的问题，我相信我的非常具体的问题没有在其他线索中回答过（我已经搜索过，对不起，如果它是重复的）。 对于企业来说：考虑下一个签名： A： void MyFunction(long int x); B： void MyFunction(long int & x); 和下一个用法： void main() { short int y = 0; MyFunction(y); ... } 我的问题与MyFunction的内存堆栈帧中
This question already has an answer here: What's the difference between passing by reference vs. passing by value? 18 answers When passing a variable by reference, whatever changes you make to it in the function are reflected back in the calling function. On the other hand, when you pass a variable by value, the changes made to it are local, and hence not reflected in the calling funct
这个问题在这里已经有了答案： 传递引用与价值传递之间有什么区别？ 18个答案 当通过引用传递一个变量时，在函数中对它做出的任何更改都会反映回调用函数中。 另一方面，当您通过值传递变量时，对其所做的更改是本地的，因此不会在调用函数中反映出来。 例如， #include "iostream" using namespace std; void function1(int &x, int y) // x passed by reference { x+=y; } void function2(int x, int y) //
Possible Duplicate: What's the difference between passing by reference vs. passing by value? If I have a function that takes in some parameters and then does something with the parameters without needing to change their inherent value, is there any benefit from using pass by reference versus pass by value? Yes. Passing by value copies the argument, which might be very expensive (or not
可能重复： 传递引用与价值传递之间有什么区别？ 如果我有一个函数接受一些参数，然后在不需要改变其固有值的情况下对参数进行一些操作，那么使用传递参考与传值是否有什么好处？ 是。 通过价值传递参数可能非常昂贵（甚至不可能）。 如果你想通过引用传递，但不修改对象，请通过const -reference传递。 作为无法按值传递的对象的示例： class Foo { public: Foo() {} private: Foo(const Foo&); // copy-
This question already has an answer here: What's the difference between passing by reference vs. passing by value? 18 answers You need to pass booklist by reference: void UpdateOnIsbn(vector <CBooks>& booklist) Otherwise the vector is copied and only this copy is modified. You are passing a copy of booklist so you are modifying the copy not the original object. Try passin
这个问题在这里已经有了答案： 传递引用与价值传递之间有什么区别？ 18个答案 您需要通过参考传递booklist ： void UpdateOnIsbn(vector <CBooks>& booklist) 否则，矢量将被复制，只有该副本被修改。 你逝去的副本booklist ，所以你要修改的副本而不是原始对象。 尝试传递函数void UpdateOnIsbn(vector <CBooks>& booklist)的引用void UpdateOnIsbn(vector <CBooks>& booklist)
This question already has an answer here: What's the difference between passing by reference vs. passing by value? 18 answers int& foo() is a function returning a (lvalue) reference to an integer. A reference is like a pointer, but unlike a pointer it has no identity of its own. It is an alias to its target, instead of the address of its target, logically. Often references are i
这个问题在这里已经有了答案： 传递引用与价值传递之间有什么区别？ 18个答案 int& foo()是一个函数，它返回一个整数的（左值）引用。 引用就像一个指针，但不同于指针，它没有自己的身份。 它是目标的别名，而不是逻辑上的目标地址。 通常引用是作为指针来实现的，但引用的意义在于编译器经常可以完全删除它们的存在。 用指针来做这件事通常比较困难，因为他们的身份与他们所指的不同。 C ++没有办法获得引用
This question already has an answer here: What is a reference-to-pointer? 2 answers What's the difference between passing by reference vs. passing by value? 18 answers First, let's add some "meat" to a : void a1(SomeType *s) { s = new SomeType; } void a2(SomeType *&s) { s = new SomeType; } Now assume you have this code, which calls a : void func() { S
这个问题在这里已经有了答案： 什么是参考指针？ 2个答案 传递引用与价值传递之间有什么区别？ 18个答案 首先，让我们添加一些“肉”到a ： void a1(SomeType *s) { s = new SomeType; } void a2(SomeType *&s) { s = new SomeType; } 现在，假设你有这样的代码，它调用a ： void func() { SomeType *p1 = nullptr; a1(p1); if (p == nullptr) std::cout << "p1 is null" <&l