C++ 扩展初始化列表仅适用于
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原文地址: http://stackoverflow.com/questions/21579654/
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extended initializer lists only available with
提问by Christian Gardner
I'm very new to C++ and I'm having trouble reading my errors I was able to eliminate most of them but I'm down to a few and I'm request help on them please.
我对 C++ 很陌生，我在阅读错误时遇到了麻烦，我能够消除其中的大部分错误，但我只剩下少数几个，请寻求帮助。
Here is the program
这是程序
#include <string>
#include <iostream>
using namespace std;
int main(){
int *bN = new int[9];
string bankNum;
int *number = new int[9];
int total, remain;
int *multi = new int{7,3,9,7,3,9,7,3};
cout<<"Please enter the bank number located at the bottom of the check"<<endl;
cin>>bankNum;
for(int i = 0; i < 8; i++){
bN[i]= (bankNum[i]-48);
}
for(int i = 0; i < 8;i++){
cout<<bN[i];
}
cout<<endl;
for(int i = 0; i < 8;i++){
cout<<multi[i];
}
cout<<endl;
for(int i = 0; i < 8;i++){
bN[i] = bN[i] * multi[i];
cout<< bN[i];
}
cout<<endl;
for(int i = 0; i < 8;i++){
total += bN[i]
cout<<total;
}
cout<<endl;
remain = total % 10;
if(remain == (bankNum[9] - 48)){
cout<<"The Number is valad"<<endl;
cout<<remain<<endl;
}
}
and the errors
和错误
wm018@cs:~$ c++ bankNum.cpp
bankNum.cpp: In function aint main()a:
bankNum.cpp:9:19: warning: extended initializer lists only available with -std=c++0x or -std=gnu++0x [enabled by default]
bankNum.cpp:9:38: error: cannot convert a<brace-enclosed initializer list>a to ainta in initialization
bankNum.cpp:30:3: error: expected a;a before acouta
回答by Mike Seymour
This style of initialisation, using braces:
这种初始化风格，使用大括号：
int *multi = new int{7,3,9,7,3,9,7,3};
was introduced to the language in 2011. Older compilers don't support it; some newer ones (like yours) only support it if you tell them; for your compiler:
于 2011 年引入该语言。较旧的编译器不支持它；一些较新的（比如你的）只有在你告诉他们时才会支持它；对于您的编译器：
c++ -std=c++0x bankNum.cpp
However, this form of initialisation still isn't valid for arrays created with new. Since it's small and only used locally, you could declare a local array; this doesn't need C++11 support:
但是，这种形式的初始化对于使用new. 由于它很小而且只在本地使用，你可以声明一个本地数组；这不需要 C++11 支持：
int multi[] = {7,3,9,7,3,9,7,3};
This also has the advantage of fixing the memory leak - if you use newto allocate memory, then you should free it with deletewhen you've finished with it.
这也有修复内存泄漏的优点——如果你new用来分配内存，那么你应该delete在完成后释放它。
If you did need dynamic allocation, you should use std::vectorto allocate and free the memory for you:
如果确实需要动态分配，则应使用std::vector为您分配和释放内存：
std::vector<int> multi {7,3,9,7,3,9,7,3};
Beware that your version of GCC is quite old, and has incomplete support for C++11.
请注意，您的 GCC 版本很旧，并且对 C++11 的支持不完整。
