C++ 错误：隐式声明的定义
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C++ error: definition of implicitly-declared
提问by Leslie Zhou
I'm writing this linked list program with C++
我正在用 C++ 编写这个链表程序
When I test the program, I got the error
当我测试程序时，出现错误
linkedlist.cpp:5:24: error: definition of implicitly-declared 'constexpr LinkedList::LinkedList()' LinkedList::LinkedList(){
Linkedlist.cpp:5:24: 错误：隐式声明的定义'constexpr LinkedList::LinkedList()' LinkedList::LinkedList(){
Here's the code
这是代码
linkedlist.h file:
链表.h文件：
#include "node.h"
using namespace std;
class LinkedList {
Node * head = nullptr;
int length = 0;
public:
void add( int );
bool remove( int );
int find( int );
int count( int );
int at( int );
int len();
};
linkedlist.cpp file:
链表.cpp文件：
#include "linkedlist.h"
#include <iostream>
using namespace std;
LinkedList::LinkedList(){
length = 0;
head = NULL;
}
/*and all the methods below*/
please help.
请帮忙。
回答by CinCout
Declare the parameterless constructor in the header file:
在头文件中声明无参数构造函数：
class LinkedList {
{
....
public:
LinkedList();
....
}
You are defining it in the .cpp file without actually declaring it. But since the compiler provides such a constructor by default (if no other constructor is declared), the error clearly states that you are trying to define an implicitly-declared constructor.
您是在 .cpp 文件中定义它而不实际声明它。但是由于编译器默认提供了这样的构造函数（如果没有声明其他构造函数），错误清楚地表明您正在尝试定义一个隐式声明的构造函数。
