I have a problem with this struct contructor when I try to compile this code:
typedef struct Node
{
Node( int data ) //
{
this->data = data;
previous = NULL; // Compiler indicates here
next = NULL;
}
int data;
Node* previous;
Node* next;
} NODE;
when I come this error occurs:
\linkedlist\linkedlist.h||In constructor `Node::Node(int)':|
\linkedlist\linkedlist.h|9|error: `NULL' was not declared in this scope|
||=== Build finished: 1 errors, 0 warnings ===|
Last problem was the struct, but it worked fine when it was in my main.cpp, this time it's in a header file and is giving me this problem. I am using Code::Blocks to compile this code
NULL
is not a built-in constant in the C or C++ languages. In fact, in C++ it's more or less obsolete, just use a plain literal 0
instead, the compiler will do the right thing depending on the context.
In newer C++ (C++11 and higher), use nullptr
(as pointed out in a comment, thanks).
Otherwise, add
#include <stddef.h>
to get the NULL
definition.