How can I remove last character from a C++ string?
I tried st = substr(st.length()-1); But it didn't work.
11 Answers
Simple solution if you are using C++11. Probably O(1) time as well:
st.pop_back();For a non-mutating version:
st = myString.substr(0, myString.size()-1);if (str.size () > 0) str.resize (str.size () - 1);An std::erase alternative is good, but I like the "- 1" (whether based on a size or end-iterator) - to me, it helps expresses the intent.
BTW - Is there really no std::string::pop_back ? - seems strange.
5buf.erase(buf.size() - 1);This assumes you know that the string is not empty. If so, you'll get an out_of_range exception.
That's all you need:
#include <string> //string::pop_back & string::empty
if (!st.empty()) st.pop_back();str.erase( str.end()-1 )
Reference: std::string::erase() prototype 2
no c++11 or c++0x needed.
6int main () { string str1="123"; string str2 = str1.substr (0,str1.length()-1); cout<<str2; // output: 12 return 0;
}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 endstr.erase(str.begin() + str.size() - 1)
str.erase(str.rbegin()) does not compile unfortunately, since reverse_iterator cannot be converted to a normal_iterator.
C++11 is your friend in this case.
2#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 the length is non zero, you can also
str[str.length() - 1] = '\0';
