String.resize()

void resize (size_t n);
void resize (size_t n, char c);
 
测试代码：

// resizing string
#include <iostream>
#include <string>
 
int main ()
{
  std::string str ("I like to code in C");
  std::cout << str << '\n';
 
  unsigned sz = str.size();
 
  str.resize (sz+2,'+');
  std::cout << str << '\n';
 
  str.resize (14);
  std::cout << str << '\n';
  return 0;
}