Question

split函数用于擦除字符串中除字母和空格外的字符。然后将其拆分为单词并将其存储在矢量中。像这样输入：apple isnot4me 输出：“apple”“isnotme”

但phase.erase(phase.begin() + index);似乎不起作用。

这是我在C ++中的程序

#include <iostream>
#include <string>
#include <vector>
using namespace std;

const string ALPHABET("abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ ");

void split(vector<string> &words, const string &phase)
{
    int pos = 0, size = 0, index = 0;

    //erace the chracters except for letters and spaces
    while((index = phase.find_first_not_of(ALPHABET, pos)) != string::npos)
    {
        phase.erase(phase.begin() + index);
        pos = index;
    }

    pos = 0, size = 0, index = 0; //initialize again

    while((index = phase.find_first_of(" ", pos)) != string::npos)
    {
        size = index - pos;
        words.push_back(phase.substr(pos, size));
        pos = index + 1;
    }

    //add the last word(if exists) to the vector words
    size = phase.length() - pos;
    words.push_back(phase.substr(pos, size));
}
int main()
{
    vector<string> words;
    string str;

    cin >> str;

    split(words, str);

    int size = words.size();

    for(int i = 0; i < size; i++)
    {
        cout << "\"" << words[i] << "\"" << ' ';
    }

    cout << endl;

    return 0;
}

然而，当我在另一个程序中独立尝试str.erase（str.begin（）+ index）时，像这样

#include <iostream>
#include <vector>
using namespace std;
int main()
{
    string str("Hello world!");
    int index = str.find_first_of(" ", 0);
    str.erase(str.begin() + index);

    cout << str << endl;

    return 0;
}

它有效！

Answer 1

您将阶段作为 const 字符串传递：

void split(vector<string> &words, const string &phase)

令人惊讶的是你可以编译，因为擦除不是常量...（不应该是）

为什么我不能在C ++中使用str.erase（str.begin（）+ index）擦除字符串中的字符？

1 个答案: