Strings

In C++, a string is an object that represents a sequence of characters. Historically, C used "Character Arrays" (C-style strings), but modern C++ uses the <string> class, which is much safer and easier to use.

1. C-style Strings vs. C++ Strings

• C-style: An array of characters ending with a null character \0.

  • Example: char name[] = "Alex"; (Actually stored as ['A', 'l', 'e', 'x', '\0']).

• C++ String Class: A dynamic object that grows as needed and has built-in functions.

  • Example: string name = "Alex";

2. Useful String Functions

The <string> library gives you "superpowers" to manipulate text:

• .length() or .size(): Returns the number of characters.

• .append() or +: Joins two strings together (Concatenation).

• [index]: Accesses a specific character (just like an array).

• .empty(): Checks if the string has no text.

Code Example: Text Processing

This program takes a username, cleans it up, and checks its properties.

#include <iostream>
#include <string> // Must include this!
using namespace std;

int main() {
    string firstName = "Master";
    string lastName = "Coder";
    
    // 1. Concatenation (Joining)
    string fullName = firstName + " " + lastName;
    cout << "Full Name: " << fullName << endl;

    // 2. Getting Length
    cout << "Length of name: " << fullName.length() << " characters." << endl;

    // 3. Accessing and Modifying characters
    cout << "First letter: " << fullName[0] << endl;
    fullName[0] = 'm'; // Changing 'M' to 'm'
    cout << "Modified Name: " << fullName << endl;

    // 4. Taking a full line of input (with spaces)
    string bio;
    cout << "Enter a short bio: ";
    getline(cin >> ws, bio); // ws skips leading whitespace
    cout << "Your bio is: " << bio << endl;

    // 5. Comparison
    if (firstName == "Master") {
        cout << "Greeting, Master!" << endl;
    }

    return 0;
}