The basic_string member class, assign() C++ program example
Compiler: Visual C++ Express Edition 2005
Compiled on Platform: Windows XP Pro SP2
Header file: Standard
Additional library: none/default
Additional project setting: Set project to be compiled as C++
Project -> your_project_name Properties -> Configuration Properties -> C/C++ -> Advanced -> Compiled As: Compiled as C++ Code (/TP)
Other info: none
To do: Using the basic_string class member, assign() to assign new character values to the contents of a string in C++ programming
To show: How to use assign() to assign new character values to the contents of a string in C++ programming
// the basic_string class member, assign() C++ example
#include <string>
#include <iostream>
using namespace std;
int main(void)
{
// the first member function assigning the characters of a C-string to a string
string str1a;
const char *cstr1a ="Out There";
cout << "The C-string cstr1a is: " << cstr1a << "." << endl;
str1a.assign (cstr1a);
cout << "Assigning the C-string cstr1a to string str1 gives: "
<< str1a << "." << endl << endl;
// the second member function assigning a specific number of the of characters a C-string to a string
string str1b;
const char *cstr1b ="Out There";
cout << "The C-string cstr1b is: " << cstr1b << endl;
str1b.assign (cstr1b , 3);
cout << "Assigning the 1st part of the C-string cstr1b "
<<"to string str1 gives: " << str1b << "."
<< endl << endl;
// the third member function assigning a specific number of the characters from one string to another string
string str1c ("Hello "), str2c ("Wide World ");
cout << "The string str2c is: " << str2c << endl;
str1c.assign (str2c , 5 , 5);
cout << "The newly assigned string str1 is: "
<< str1c << "." << endl << endl;
// the fourth member function assigning the characters from one string to another string in two equivalent ways, comparing the assign and operator =
string str1d ("Hello"), str2d ("Wide"), str3d ("World");
cout << "The original string str1 is: " << str1d << "." << endl;
cout << "The string str2d is: " << str2d << endl;
str1d.assign (str2d);
cout << "The string str1 newly assigned with string str2d is: "
<< str1d << "." << endl;
cout << "The string str3d is: " << str3d << "." << endl;
str1d = str3d;
cout << "The string str1 reassigned with string str3d is: "
<< str1d << "." << endl << endl;
// the fifth member function assigning a specific number of characters of a certain value to a string
string str1e ("Hello ");
str1e.assign (4 , '!');
cout << "The string str1 assigned with exclamations is: "
<< str1e << endl << endl;
// the sixth member function assigning the value from the range of one string to another string
string str1f ("Hello "), str2f ("Wide World ");
cout << "The string str2f is: " << str2f << endl;
str1f.assign(str2f.begin() + 5 , str2f.end() - 1);
cout << "The string str1 assigned a range of string str2f is: "
<< str1f << "." << endl << endl;
return 0;
}
Output example:
The C-string cstr1a is: Out There.
Assigning the C-string cstr1a to string str1 gives: Out There.
The C-string cstr1b is: Out There
Assigning the 1st part of the C-string cstr1b to string str1 gives: Out.
The string str2c is: Wide World
The newly assigned string str1 is: World.
The original string str1 is: Hello.
The string str2d is: Wide
The string str1 newly assigned with string str2d is: Wide.
The string str3d is: World.
The string str1 reassigned with string str3d is: World.
The string str1 assigned with exclamations is: !!!!
The string str2f is: Wide World
The string str1 assigned a range of string str2f is: World.
Press any key to continue . . .