错误:预期在"="，“，"，“;"，"asm"或"__attribute__"之前

问题描述

是的，我知道这个问题以前已经被问过无数次了，但是由于我无法确定通常缺少的分号在哪里，所以我竭尽全力试图找出导致错误的原因.

Yes, I know this question has been asked numerous times previously, however I am racking my brain trying to figure out what is causing the error as I cannot identify where the usual missing semi-colon is.

list.h

/* list.h  */

#ifndef _LIST_H
#define _LIST_H

#define TRUE_ true
#define FALSE_ false

class LISTElement {
   public:
     LISTElement(void *itemPtr, int sortKey);  /* initialize a list element */
     LISTElement *next;         /* next element on list,
                                   NULL if this is the last */
     int key;                   /* priority, for a sorted list */
     void *item;                /* pointer to item on the list */
};

class LIST {
  public:
    LIST();                     /* initialize the list  */
    ~LIST();                    /* de-allocate the list */

    bool IsEmpty();             /* is the list empty? */
    void Insert(void *item, int sortKey);       /* Put item into list */
    void *Remove(int *keyPtr);          /* Remove first item from list */

  private:
    LISTElement *first;         /* Head of the list, NULL if list is empty */
    LISTElement *last;          /* Last element of list */
};

#endif /* _LIST_H */

list.c

#include <stdlib.h>
#include "list.h"

LISTElement::LISTElement(void *itemPtr, int sortKey) {
     item = itemPtr;
     key = sortKey;
     next = NULL;       /* assume we'll put it at the end of the list */
}

LIST::LIST() {
    first = last = NULL;
}

LIST::~LIST() {
    while (Remove(NULL) != NULL)
        ;        // delete all the list elements
}

bool LIST::IsEmpty() {
    if (first == NULL)
        return TRUE_;
    else
        return FALSE_;
}

void LIST::Insert(void *item, int sortKey) {
    LISTElement *element = new LISTElement(item, sortKey);
    LISTElement *ptr;

    if (IsEmpty()) {    /* if list is empty, put */
        first = element;
        last = element;
    } else if (sortKey < first->key) {
                /* item goes on front of list */
        element->next = first;
        first = element;
    } else {            /* look for first element in list bigger than item */
        for (ptr = first; ptr->next != NULL; ptr = ptr->next) {
            if (sortKey < ptr->next->key) {
                element->next = ptr->next;
                ptr->next = element;
                return;
            }
        }
        last->next = element;           /* item goes at end of list */
        last = element;
    }
}

void * LIST::Remove(int *keyPtr) {
    LISTElement *element = first;
    void *thing;

    if (IsEmpty())
        return NULL;

    thing = first->item;
    if (first == last) {        /* list had one item, now has none */
        first = NULL;
        last = NULL;
    } else {
        first = element->next;
    }
    if (keyPtr != NULL)
        *keyPtr = element->key;
    delete element;
    return thing;
}

编译器抛出的错误:

$ gcc -o list list.c
In file included from list.c:2:
list.h:9: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘LISTElement’
list.h:18: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘LIST’
list.c:4: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
list.c:10: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
list.c:14: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
list.c:19: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘LIST’
list.c:26: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token
list.c:50: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘:’ token

推荐答案

这次不是缺少分号，而是一种完全不同的语言.您尝试编译的代码是C ++，而不是C.这就是为什么您从C编译器收到语法错误的原因.

This time it's not a missing semicolon, but a completely different language. The code you're trying to compile is in C++, not C. That's why you get syntax errors from a C compiler.

要解决此问题(并将代码编译为C ++)，请将文件从 .c 重命名为 .cpp :

To fix this (and compile the code as C++), rename the file from .c to .cpp:

mv list.c list.cpp

并使用 g ++ 进行编译，而不是 gcc :

And use g++ to compile it, not gcc:

g++ -o list list.cpp

这篇关于错误:预期在"="，“，"，“;"，"asm"或"__attribute__"之前的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！