String Operations

Strings in C++

C++ std::string is a major improvement over C's null-terminated char* arrays. It manages memory automatically and comes with many built-in methods.

Creating Strings

#include <string>
using namespace std;

string name = "Alice";
string empty = "";
string repeated(5, 'x');  // "xxxxx"

Concatenation

Use + to combine strings:

string first = "Hello";
string second = "World";
string combined = first + ", " + second + "!";
// "Hello, World!"

Use += to append:

string s = "foo";
s += "bar";  // "foobar"

Length

string s = "hello";
cout << s.length() << endl;  // 5
cout << s.size() << endl;    // also 5

Substrings

substr(pos, length) extracts a portion of the string:

string s = "Hello, World!";
cout << s.substr(0, 5) << endl;  // Hello
cout << s.substr(7, 5) << endl;  // World

Finding Substrings

find returns the index of the first match, or string::npos if not found:

string s = "Hello, World!";
int pos = s.find("World");   // 7
int pos2 = s.find("xyz");    // string::npos

Comparing Strings

Use == and != directly:

string a = "hello";
string b = "hello";
if (a == b) cout << "equal" << endl;

Your Task

Build a sentence and then:

1. Print the combined string
2. Print its length
3. Print the first 5 characters (using substr)