如何从“ v％d。％d。％d”字符串格式中提取3个整数？

Question

我正在尝试从具有以下格式的语义版本字符串中提取3个数字："v%d.%d.%d"

这是我的示例代码：

std::string myVersion = "v3.49.1";
int versionMajor, versionMinor, versionPatch;
getVersionInfo(myVersion, versionMajor, versionMinor, versionPatch);
std::cout << versionMajor << " " << versionMinor << " " << versionPatch << '\n';

预期结果：

3 49 1

如何设计功能getVersionInfo()？

最优雅的解决方案是什么？

Answer 1

使用sscanf：

void getVersionInfo(std::string version, int &major, int &minor, int &patch) {
    sscanf(version.c_str(), "v%d.%d.%d", &major, &minor, &patch);
}

Try it here

Answer 2

也许您可以尝试

#include <iostream>
using namespace std;

int main() {
    string s="v3.49.1";
    int major,minor,patch;
    int x=s.find(".");

    //We dont want v symbol so start from 1 till 1st dot
    major=stoi(s.substr(1,x));
    cout<<major;

    //Then find second dot from first symbol and copy as sub string
    int y=s.find(".",x+1);
    minor=stoi(s.substr(x+1,y-x));
    cout<<minor;

    //After that remaining string will be patch version
    patch=stoi(s.substr(y+1));
    cout<<patch;
    return 0;
}