c++ - ispunct() 不删除字符串中间的逗号

Question

我有一个字符串，包括:

UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity.

我有下面的代码应该去除这个字符串中的所有标点符号。测试变量是我的字符串:

 if(std::ispunct(test[test.length()-1]))
    {
        test.erase(test.length()-1, 1);
    }

然而，当我在这个函数之后再次输出这个字符串时，我有以下内容:

UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity

出于某种原因，ispunct 函数能够去除句号但不能去除逗号。为什么它以这种方式表现？提前致谢。

Answer 1

看起来您正在寻找 remove_if algorithm (连同 ispunct predicate )。

注意:

A call to remove is typically followed by a call to a container's erase method, which erases the unspecified values and reduces the physical size of the container to match its new logical size.

#include <algorithm>
#include <cctype>
#include <iostream>
#include <string>

int main()
{
    std::string dmr = "UNIX is basically a simple operating system, but you have to be a genius to understand the simplicity.";
    auto last = std::remove_if(dmr.begin(), dmr.end(), ispunct);
    dmr.erase(last, dmr.end());
    std::cout << dmr << std::endl;
}

See it run!