错误“在定义方法时，C++ 要求所有声明都使用类型说明符”
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Error "C++ requires a type specifier for all declarations whilst defining methods"
提问by Lorienas
I'm relatively new to C++ (so try and keep answers simple please!), and I can't understand why I get the error: C++ requires a type specifier for all declarations whilst defining methods.
我对 C++ 比较陌生（所以请尽量保持答案简单！），我不明白为什么会出现错误： C++ requires a type specifier for all declarations whilst defining methods.
I am trying to write a simple program to read a text file line by line, store the values into an array. However I am encountering an issue when trying to declare methods in my .cpp file. Please find code below.
我正在尝试编写一个简单的程序来逐行读取文本文件，将值存储到数组中。但是，当我尝试在我的 .cpp 文件中声明方法时遇到了一个问题。请在下面找到代码。
StringList.h
字符串列表.h
#ifndef StringListH
#define StringListH
#include <vector>
#include <string>
class StringList {
public:
StringList();
~StringList();
void PrintWords();
private:
size_t numberOfLines;
std::vector<std::string> str;
};
#endif
StringList.cpp
字符串列表.cpp
#include "StringList.h"
#include <fstream>
#include <istream>
#include <algorithm> // std::copy
#include <iterator> // istream_iterator
using namespace std;
StringList::StringList()
{
ifstream myfile("input.in");
if (myfile.is_open())
{
copy(
istream_iterator<string>(myfile),
istream_iterator<string>(),
back_inserter(str));
}
numberOfLines = str.size();
}
StringList::~StringList(){
//Deconstructor
}
// Error Happens Here
StringList::PrintWords(){
//Print My array
}
I have googled to no avail, I don't quite understand how to read the proper documentation for C++ yet, so I'm a little stuck. I have written around 3 or 4 (simple) object orientated programs so far and I've never had this issue. If it helps I'm using Xcode, but I get the same error in eclipse.
我用谷歌搜索无济于事，我还不太明白如何阅读 C++ 的正确文档，所以我有点卡住了。到目前为止，我已经编写了大约 3 或 4 个（简单的）面向对象的程序，但我从未遇到过这个问题。如果它有助于我使用 Xcode，但我在 eclipse 中遇到相同的错误。
It appears any method, regardless of return type, name, parameters defined in my head file give this error - however the constructor is fine. If PrintWords() is remove the project builds just fine.
似乎任何方法，无论返回类型、名称、参数在我的头文件中定义如何都会出现此错误 - 但是构造函数很好。如果 PrintWords() 被删除，项目构建就好了。
Any pointers will be very much appreciated!
任何指针将不胜感激！
回答by stellarossa
you declared it as voidbut you forgot to put it in the definition. should be:
您将其声明为，void但您忘记将其放入定义中。应该：
void StringList::PrintWords()
void StringList::PrintWords()
回答by 0x499602D2
Your member function PrintWordsis prototyped as:
您的成员函数PrintWords原型为：
void PrintOn();
Meaning it returns void. When you implement your function elsewhere you still have to provide the return type, which you've mistakenly left out:
意思是它返回void。当你在别处实现你的函数时，你仍然需要提供返回类型，你错误地忽略了它：
/* void */ StringList::PrintOn() { ... }
回答by Scott Mermelstein
Put a voidin front of the line giving you issues.
void在给你问题的行前面放一个。
Even though it feels redundant, you have to specify the return type both in the declaration and the implementation.
即使感觉多余，您也必须在声明和实现中指定返回类型。
