basic_string::operator =

指定新的字元值至字串的內容。

basic_string<CharType, Traits, Allocator>& operator=(
   value_type _Ch
);
basic_string<CharType, Traits, Allocator>& operator=(
   const value_type* _Ptr
);
basic_string<CharType, Traits, Allocator>& operator=(
   const basic_string<CharType, Traits, Allocator>& _Right
);
basic_string<CharType, Traits, Allocator>& operator=(
   const basic_string<CharType, Traits, Allocator>&& _Right
);

參數

• _Ch
  將指定的字元值。

• _Ptr
  將指定的C字串的字元指標到目標字串。

• _Right
  字元會指派給目標字串的來源字串。

傳回值

在成員函式指定新的字串物件的參考。

備註

字串可以指定新的字元值。 新的值可能是字串和C字串或單一字元。 可以使用 operator= ，如果新值可以由單一參數描述，否則成員函式 指定，有多個參數，可以用來指定字串的哪個部分要指派給目標字串。

範例

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

int main( ) 
{
   using namespace std;

   // The first member function assigning a
   // character of a certain value to a string
   string str1a ( "Hello " );
   str1a = '0';
   cout << "The string str1 assigned with the zero character is: " 
        << str1a << endl << endl;

   // The second member function assigning the
   // characters of a C-string to a string
   string  str1b;
   const char *cstr1b = "Out There";
   cout << "The C-string cstr1b is: " << cstr1b <<  "." << endl;
   str1b = cstr1b;
   cout << "Assigning the C-string cstr1a to string str1 gives: " 
        << str1b << "." << endl << endl;

   // The third member function assigning the characters
   // from one string to another string in two equivalent
   // ways, comparing the assign and operator =
   string str1c ( "Hello" ), str2c ( "Wide" ), str3c ( "World" );
   cout << "The original string str1 is: " << str1c << "." << endl;
   cout << "The string str2c is: " << str2c << "." << endl;
   str1c.assign ( str2c );
   cout << "The string str1 newly assigned with string str2c is: " 
        << str1c << "." << endl;
   cout << "The string str3c is: " << str3c << "." << endl;
   str1c = str3c;
   cout << "The string str1 reassigned with string str3c is: " 
        << str1c << "." << endl << endl;
}

需求

標題: <string>

命名空間: std

請參閱

參考

basic_string Class