The following example illustrates several of the fundamental string operations:H e r b S c h i l d t ' s C + + P r o g r a m m i n g C o o k b o o k

The following example illustrates several of the fundamental string operations:
// Demonstrate the basic string operations.
#include <iostream>
#include <string>
using namespace std;
int main()
{
// Create some string objects. Three are initialized
// using the string literal passed as an argument.
string str1("Alpha");
string str2("Beta");
string str3("Gamma");
string str4;
// Output a string via cout.
cout << "Here are the original strings:\n";
cout << " str1: " << str1 << endl;
cout << " str2: " << str2 << endl;
cout << " str3: " << str3 << "\n\n";
// Display the maximum string length.
cout << "The maximum string length is: " << str1.max_size()
<< "\n\n";
// Display the size of str1.
cout << "str1 contains " << str1.size() << " characters.\n";
// Display the capacity of str1.
cout << "Capacity of str1: " << str1.capacity() << "\n\n";
// Display the characters in a string one at a time
// by using the indexing operator.
for(unsigned i = 0; i < str1.size(); ++i)
cout << "str1[i]: " << str1[i] << endl;
cout << endl;
// Assign one string to another.
str4 = str1;
cout << "str4 after being assigned str1: " << str4 << "\n\n";

// Concatenate two strings.
str4 = str1 + str3;
cout << "str4 after begin assigned st1+str3: " << str4 << "\n\n";
// Insert one string into another.
str4.insert(5, str2);
cout << "str4 after inserting str2: " << str4 << "\n\n";
// Obtain a substring.
str4 = str4.substr(5, 4);
cout << "str4 after being assigned str4.substr(5, 3): "
<< str4 << "\n\n";
// Compare two strings.
cout << "Compare strings.\n";
if(str3 > str1) cout << "str3 > str1\n";
if(str3 == str1+str2)
cout << "str3 == str1+str2\n";
if(str1 <= str2)
cout << "str1 <= str2\n\n";
// Create a string object using another string object.
cout << "Initialize str5 with the contents of str1.\n";
string str5(str1);
cout << "str5: " << str5 << "\n\n";
// Erase str4.
cout << "Erasing str4.\n";
str4.erase();
if(str4.empty()) cout << "str4 is now empty.\n";
cout << "Size and capacity of str4 is " << str4.size() << " "
<< str4.capacity() << "\n\n";
// Use push_back() to add characters to str4.
for(char ch = 'A'; ch <= 'Z'; ++ch)
str4.push_back(ch);
cout << "str4 after calls to push_back(): " << str4 << endl;
cout << "Size and capacity of str4 is now " << str4.size() << " "
<< str4.capacity() << "\n\n";
// Set the capacity of str4 to 128.
cout << "Setting the capacity of str4 to 128\n";
str4.reserve(128);
cout << "Capacity of str4 is now: " << str4.capacity() << "\n\n";
// Input a string via cin.
cout << "Enter a string: ";
cin >> str1;
cout << "You entered: " << str1 << "\n\n";
return 0;
}