将字符串拆分为向量 <string> 通过多个字符串定界符

Question

在C ++中，不使用任何boost例程，我们知道如何：

• 用单个char值或多个char值分割字符串

• 用一个字符串值分割一个字符串：

   void ParseStringByStringSeparator(string s, const string separator, vector<string>& result) { result.clear(); size_t pos = 0; string token; while ((pos = s.find(separator)) != string::npos) { token = s.substr(0, pos); result.push_back(token); s.erase(0, pos + separator.length()); } result.push_back(s); } 

但是，如何将一个字符串除以多个字符串值呢？

例如，如果我具有以下字符串值"Hello I am a String"而分隔符为" "和"am"那么我想获得以下vector<string>值：

{"Hello","I","a","String"}

有什么提示吗？

Answer 1

此功能可以执行您想要的操作。 它基本上在定界符的向量上进行迭代，并对每个函数应用您的函数：

vector<string> SplitStringMultipleStrParameters(string s,const vector<string>& separators) {

    //The result to be returned
    vector<string> result = { s };

    //Iterate on the list of separators, so for each separators
    for (const auto& sep : separators) {
        //toReplaceBy will be the next vector of strings where it will iterate
        vector<string> toReplaceBy, tempRes;

        //For each strings, we will split on "sep", the separator
        for (auto&a : result) {
            //Because of the result vector being cleared every time your function get called
            //It get in a temp vector that we will concatenate after
            ParseStringByStringSeparator(a, sep, tempRes);
            //Concatenation of theses vectors
            toReplaceBy.insert(toReplaceBy.end(), tempRes.begin(), tempRes.end());
        }

        //Erasing all strings that are empty. C++11 code here required because of the lambda
        toReplaceBy.erase(std::remove_if(toReplaceBy.begin(), toReplaceBy.end(),
            [](const std::string& i) {
            return i == "";
        }), toReplaceBy.end());

        //The vector containing strings to be splited is replaced by the split result on this iteration
        result = toReplaceBy;
        //And we will split those results using the next separator, if there's more separator to iterate on
    }
    return result;
}

测试代码：

string test = "Hello I am a string";

auto r = SplitStringMultipleStrParameters(test, { " ", "am" });

for (auto& a : r) {
    std::cout << a << '\n';
}

它需要使用C ++ 11编译器进行编译，并且需要包含<algorithm>标头。

如果您的编译器未编译C ++ 11代码，则此函数为：

vector<string> SplitStringMultipleStrParameters(string s,const vector<string>& separators) {
    vector<string> result = { s };
    for (const auto& sep : separators) {
        vector<string> toReplaceBy, tempRes;
        for (auto&a : result) {
            ParseStringByStringSeparator(a, sep, tempRes);
            toReplaceBy.insert(toReplaceBy.end(), tempRes.begin(), tempRes.end());
        }
        auto it = toReplaceBy.begin();
        while (it != toReplaceBy.end()) {
            if ((*it) == "")
                it = toReplaceBy.erase(it);
            else
                ++it;
        }
        result = toReplaceBy;
    }
    return result;
}