Difference between revisions of "cpp/string/basic string/at"
From cppreference.com
< cpp | string | basic string
m |
m (Catch exceptions by const reference) |
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| Line 49: | Line 49: | ||
s.at(3) = 'x'; | s.at(3) = 'x'; | ||
} | } | ||
| − | catch (std::out_of_range& exc) { | + | catch (std::out_of_range const& exc) { |
std::cout << exc.what() << '\n'; | std::cout << exc.what() << '\n'; | ||
} | } | ||
Revision as of 12:12, 18 May 2014
| reference at( size_type pos ); |
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| const_reference at( size_type pos ) const; |
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Returns a reference to the character at specified location pos. Bounds checking is performed, exception of type std::out_of_range will be thrown on invalid access.
Contents |
Parameters
| pos | - | position of the character to return |
Return value
Reference to the requested character.
Exceptions
Throws std::out_of_range if pos >= size().
Complexity
Constant.
Example
Run this code
#include <stdexcept> #include <iostream> #include <string> int main() { std::string s("message"); // for capacity s = "abc"; s.at(2) = 'x'; // ok std::cout << s << '\n'; std::cout << "string size = " << s.size() << '\n'; std::cout << "string capacity = " << s.capacity() << '\n'; try { // throw, even if capacity allowed to access element s.at(3) = 'x'; } catch (std::out_of_range const& exc) { std::cout << exc.what() << '\n'; } }
Output:
abx string size = 3 string capacity = 7 basic_string::at
See also
| accesses the specified character (public member function) |
