如何知道我想在数组中存储多少索引

How to know how many index i want to store in the arrays

本文关键字：存储 多少 索引 数组 何知道      更新时间：2023-10-16

我想编写一个搜索函数，您可以在其中从文件中获取字符串。该函数要求用户输入要搜索的字符串的第一个字母，for循环将搜索第一个字母与用户请求的字符串相同的字符串。这是我的代码。

string bid, bname, bAuthor, bcat, bPub;
int bAmt = 0, i = 1;
bool bname2length;
char character[];
char firstChar;
ifstream inBook;
inBook.open("books.txt");
if(inBook.is_open())
{
    cout << setfill('-') << setw(1) << "+" << setw(3) << "-" << setw(1) << "+" << setw(8) << "-" << setw(1) << "+" << setw(40) << "-" << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << setw(20) << "-" << setw(1) << "+" << setw(20) << "-" << setw(1) << "+" << setw(6) << "-" << setw(1) << "+" << endl;
    cout << setfill(' ') << setw(1) << "|" << setw(3) << left << "No." << setw(1) << "|" << setw(8) << left << "BookID" << setw(1) << "|" << setw(40) << left << "Book Name" << setw(1) << "|" << setw(15) << left << "Author" << setw(1) << "|" << setw(20) << left << "Category" << setw(1) << "|" << setw(20) << left << "Publisher" << setw(1) << "|" << setw(6) << left << "Amount" << setw(1) << "|" << endl;
    cout << setfill('-') << setw(1) << "+" << setw(3) << "-" << setw(1) << "+" << setw(8) << "-" << setw(1) << "+" << setw(40) << "-" << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << setw(20) << "-" << setw(1) << "+" << setw(20) << "-" << setw(1) << "+" <<  setw(6) << "-" << setw(1) << "+" << endl;
    getline(inBook, bid, '#');
    getline(inBook, bname, '#');
    getline(inBook, bAuthor, '#');
    getline(inBook, bAuthor, '#');
    getline(inBook, bPub, '#');
    inBook >> bAmt;
    inBook.ignore(1);
    while(!inBook.eof())
    {
        cout << setfill(' ') << setw(1) << "|" << setw(3) << left << i << setw(1) << "|" << setw(8) << left << bid << setw(1) << "|" << setw(40) << left << bname << setw(1) << "|" << setw(15) << left << bAuthor << setw(1) << "|" << setw(20) << left << bcat << setw(1) << "|" << setw(20) << left << bPub << setw(1) << "|" << setw(6) << left << bAmt << setw(1) << "|" << endl;
        cout << setfill('-') << setw(1) << "+" << setw(3) << "-" << setw(1) << "+" << setw(8) << "-" << setw(1) << "+" << setw(40) << "-" << setw(1) << "+" << setw(15) << "-" << setw(1) << "+" << setw(20) << "-" << setw(1) << "+" << setw(20) << "-" << setw(1) << "+" << setw(6) << "-" << setw(1) << "+" << endl;
        getline(inBook, bid, '#');
        getline(inBook, bname, '#');
        getline(inBook, bAuthor, '#');
        getline(inBook, bcat, '#');
        getline(inBook, bPub, '#');
        inBook >> bAmt;
        inBook.ignore(1);
        i++;
        cout << "Enter the First Character of Search Obj : ";
        cin >> firstChar;
        while(bid != ' ')
        {
            character[i] = bid;
            i++;
        }
        cout << "Books with First Character of " + firstChar << endl;
        for(int i=0; i<sizeof(character[]); i++)
        {
            if(character[i].chatAt(0) == firstChar)
            {
                cout << character[i] << endl;
            }
        }
    }
    inBook.close();
}
else
{
    cout << "Invalid file!";
}

除了@NathanOliver很棒的帖子之外，也不需要原始数组。你会给自己带来麻烦。 使用std::vector或类似的东西。

#include <vector>
std::vector<char> bids;
while(bid != ' ')
{
     bids.push_back(bid);
}
cout << "Books with First Character of " + firstChar << endl;
// C++11 for loop..Otherwise loop with iterators.    
for (const auto& abid : bids)
{  
    cout << bid << endl;
}
相关文章：