basic_string::resize

指定字符串的一个新范围，追加或清除元素的根据要求。

void resize(
    size_type _Count, 
);
void resize(
    size_type _Count,
    _Elem _Ch
);

参数

• _Count
  字符串的新范围。

• _Ch
  值追加的字符初始化，如果需要其他元素。

备注

如果得到的大小超过的最大字符数，窗体引发 length_error。

示例

// basic_string_resize.cpp
// compile with: /EHsc
#include <string>
#include <iostream>

int main( ) 
{
   using namespace std;
   string  str1 ( "Hello world" );
   cout << "The original string str1 is: " << str1 << endl;

   basic_string <char>::size_type sizeStr1;
   sizeStr1 = str1.size ( );
   basic_string <char>::size_type capStr1;
   capStr1 = str1.capacity ( );

   // Compare size & capacity of the original string
   cout << "The current size of original string str1 is: " 
        << sizeStr1 << "." << endl;
   cout << "The capacity of original string str1 is: "
        << capStr1 << "." << endl << endl;

   // Use resize to increase size by 2 elements: exclamations
   str1.resize ( str1.size ( ) + 2 , '!' );
   cout << "The resized string str1 is: " << str1 << endl;

   sizeStr1 = str1.size ( );
   capStr1 = str1.capacity ( );

   // Compare size & capacity of a string after resizing
   cout << "The current size of resized string str1 is: " 
        << sizeStr1 << "." << endl;
   cout << "The capacity of resized string str1 is: "
        << capStr1 << "." << endl << endl;

   // Use resize to increase size by 20 elements:
   str1.resize ( str1.size ( ) + 20 );
   cout << "The resized string str1 is: " << str1 << endl;

   sizeStr1 = str1.size ( );
   capStr1 = str1.capacity ( );

   // Compare size & capacity of a string after resizing
   // note capacity increases automatically as required
   cout << "The current size of modified string str1 is: " 
        << sizeStr1 << "." << endl;
   cout << "The capacity of modified string str1 is: "
        << capStr1 << "." << endl << endl;

   // Use resize to downsize by 28 elements:
   str1.resize ( str1.size ( ) - 28 );
   cout << "The downsized string str1 is: " << str1 << endl;

   sizeStr1 = str1.size (  );
   capStr1 = str1.capacity (  );

   // Compare size & capacity of a string after downsizing
   cout << "The current size of downsized string str1 is: " 
        << sizeStr1 << "." << endl;
   cout << "The capacity of downsized string str1 is: "
        << capStr1 << "." << endl;
}

要求

标头: <string>

命名空间: std

请参见

参考

basic_string Class

basic_string::size 和 basic_string::resize