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std::basic_string::capacity

size_type capacity() const;

Returns the number of characters that the string has currently allocated space for.

Parameters

(none).

Return value

capacity of the currently allocated storage.

Exceptions

(none) (until C++11)
noexcept specification:
noexcept
 (since C++11)

Complexity

Constant.

Example

#include <iostream>
#include <string>
 
void show_capacity(std::string const& s)
{
    std::cout << "'" << s << "' has capacity " << s.capacity() << ".\n";
}
 
int main()
{
    std::string s{"Exemplar"};
    show_capacity(s);
 
    s += " is an example string.";
    show_capacity(s);
}

Possible output:

'Exemplar' has capacity 8.
'Exemplar is an example string.' has capacity 30.

See also

 returns the number of characters
(public member function)
reserves storage
(public member function)

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