错误C2143：“常量”前缺少语法错误“）”

Question

I'm a student using c++ in class. I did see this error in about three other questions, however, they were all solved by adding a basic arithmetic sign in front of a hard-coded number. As I'm not doing arithmetic, I don't think they will help me here.

For our assignment we're having to parse a bibliography and store the resulting entries into a linked list of entries. To that end, the book we're using has a linked list class, but it has errors. One of the error sets I can't figure out is:

• "error C2143: syntax error: missing ')' before 'constant.'
• "error C2143: syntax error: missing ';' before 'constant.'
• "error C2059: syntax error: missing ')'
• "error C2238: unexpected token(s) preceding ';'

The offending line(s) are in a template header, and my question is what can I do to fix this? The code can be found here:

template <class DataType>
class LinkedList : public AbstractLinkedList<DataType>{
protected:
    DataType* _info;
    LinkedList<DataType>* _next;
    void copy(const LinkedList<DataType>& 11);  //first offending line
public:
    LinkedList();
    LinkedList(const LinkedList<DataType>& ll);
    LinkedList(const DataType& info);
    LinkedList(const DataType& info, LinkedList<DataType>* next);
    ~LinkedList();
};

template <class DataType>
void LinkedList<DataType>::copy(const LinkedList<DataType>& 11){  //second offending line
    if(ll._info == NULL){
        _info = NULL;
    } else {
        _info = new DataType(*(ll._info));
        if(_info == NULL){
            throw LinkedListMemory();
        }
    }
    if(ll._next == NULL){
        _next = NULL;
    } else {
        _next = new LinkedList<DataType>(*(ll._next));
        if(_next == NULL){
            throw LinkedListMemory();
        }
    }
}

I'm skipping over parts that aren't causing errors

Things I've tried:

• changing the name from "copy" to something like "copyList"
• removing the const keyword;
• removing "LinkedList<" and ">"
• removing "<""DataType>"

none of that fixed the problem and my understanding is without the "LinkedList'<'DataType>&" it can't really be used in a template form.

Answer 1

11 (the number one, twice) is not a valid variable name; identifiers must start with a letter or underscore.

You probably meant ll (the letter "l", twice, which could stand for "linked list"). It can be hard to distinguish l from 1 in some fonts.

Answer 2

变量名不能以数字开头，因为一串数字既是有效的标识符又是有效的数字。