c++ - 我的结构是一个单词列表，必须在之后输出。但是输出格式不对

Question

因此，我必须将一个 char* 转换为我自己的结构 SList，它只是前一个数组中的单词列表(用空格分隔)，然后为其创建一个 ostream << 运算符

但这里是输出:

8° └
8°
8° └
8

怎么了？ 此外，所有输出元素似乎都相同，只是长度不同

#include <iostream>
using namespace std;

struct Word {
    int size;
    char *symbols;
};

struct SList {
    int size;
    Word *myArray;
};

SList third(char *words, int size, size_t n) {
    int indexOfMyArray = 0;
    int index = 0;
    Word *myArray = new Word[size];
    for (int i = 0; i < size; i++) {
        char *word = new char[n];
        int k = 0;
        while (words[index] >= 'a' && words[index] <= 'z') {
            word[k] = words[index];
            k++;
            index++;
        }
        word[k] = '\0';
        index++;
        Word word1 = {k, word};
        myArray[indexOfMyArray] = word1;
        indexOfMyArray++;
        cout << word << ' ';
        for (int k = 0; k < word1.size; k++)
            cout << word1.symbols[k];
        cout << endl;
        delete[](word);
    }
    cout << endl;
    SList list = {size, myArray};
    return list;
}

ostream &operator<<(ostream &os, const SList &list) {
    for (int i = 0; i < list.size; i++) {
        for (int j = 0; j < list.myArray[i].size; j++) {
            os << static_cast<char>(list.myArray[i].symbols[j]+0);
        }
        os << endl;
    }
    return os;
}

int main() {

    char chars[19] = {'e', 'z', 'e', 's', 'c', ' ', 'e', 'f', 't', ' ', 'y', 'y', 'y', 'y', 'y', 'y', ' ', 'f', 'h'};
    SList list = third(chars, 4, 19);
    cout << list << endl;

    system("pause");
}

Answer 1

如评论中所示，使用 C++ 类型可以使问题更易读和理解。

#include <iostream>
using namespace std;

using Word = std:: string;
using SList = std::vector<Word>;

SList third(std::string const &words) {
    SList myArray;
     int index = 0;
    while (index < words.size()) {
        Word word;
        while (words[index] >= 'a' && words[index] <= 'z') {
            word += words[index];
            index++;
       }   
       myArray.push_back( word);
        cout << word << ' ' << myArray.back() << std::endl;
    }
    cout << endl;
    return myArray;
}

// I believe this operator is actually undefined behavior as you ain't allowed to write this method for standard types.
ostream &operator<<(ostream &os, const SList &list)
    {
   for (auto &&word : list)
          os << word << std::endl;
    return os;
    }

int main() {

    std::string chars {"ezesc eft yyyyyy fh"};
    SList list = third(chars);
    cout << list << endl;

    system("pause");
}

以上解决了您的问题，因为内存管理突然对您隐藏了。这是好事!

在您的代码中:问题在于:delete[](word); word 的内存仍然由您存储的指针引用。因此，当访问该内存时，您有未定义的行为并且结果不是很好。你很不幸它没有崩溃。