#include<iostream>
using namespace std;
int main(){
  string s = "Hello";// Here string length is 5 initially
  s[s.length()-1] = '\0'; //  marking the last char to be null character
  s = &s[0]; // using ampersand infront of the string with index will render a string from the index until null character discovered
  cout<<"the new length of the string "<<s + " is " <<s.length();
  return 0;
}

if (str.size() > 0)  str.resize(str.size() - 1);

std::erase替代方法很好，但我喜欢- 1(无论是基于大小还是结束迭代器)-对我来说，它有助于表达意图。

BTW -真的没有std::string::pop_back吗?-看起来很奇怪。

buf.erase(buf.size() - 1);

这假设您知道字符串不是空的。如果是这样，您将得到一个out_of_range异常。

#include<iostream>
using namespace std;
int main(){
  string s = "Hello";// Here string length is 5 initially
  s[s.length()-1] = '\0'; //  marking the last char to be null character
  s = &s[0]; // using ampersand infront of the string with index will render a string from the index until null character discovered
  cout<<"the new length of the string "<<s + " is " <<s.length();
  return 0;
}

在c++ 11中，你甚至不需要长度/大小。只要字符串不为空，就可以执行以下操作:

if (!st.empty())
  st.erase(std::prev(st.end())); // Erase element referred to by iterator one
                                 // before the end

如果长度非零，也可以

str[str.length() - 1] = '\0';