Remove last character from C++ string

Question

How can I remove last character from a C++ string?

I tried st = substr(st.length()-1); But it didn\'t work.

Answer 1

Simple solution if you are using C++11. Probably O(1) time as well:

st.pop_back();

Answer 2

If the length is non zero, you can also

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

Answer 3

With C++11, you don't even need the length/size. As long as the string is not empty, you can do the following:

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

Answer 4

int main () {

  string str1="123";
  string str2 = str1.substr (0,str1.length()-1);

  cout<<str2; // output: 12

  return 0;
}

Answer 5

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

This assumes you know that the string is not empty. If so, you'll get an out_of_range exception.

Answer 6

That's all you need:

#include <string>  //string::pop_back & string::empty

if (!st.empty())
    st.pop_back();