C++ Strings
C++ has two types of strings: C-style char arrays and the modern std::string class. Always prefer std::string.
Example
#include <string>
using namespace std;
// std::string
string name = "Alice";
string greeting = "Hello, " + name; // concatenation
// String methods
cout << name.length() << endl; // 5
cout << name.at(0) << endl; // 'A'
cout << name.substr(0, 3) << endl; // "Ali"
cout << name.find("ice") << endl; // 2
name.append(" Smith"); // "Alice Smith"
name.insert(5, " J."); // "Alice J. Smith"
name.erase(5, 3); // "Alice Smith"
name.replace(6, 5, "Jones"); // "Alice Jones"
// Comparison
string a = "apple", b = "banana";
if (a < b) cout << a << " comes first" << endl;
if (a == "apple") cout << "Match!" << endl;String Input and Conversion
Reading strings from input and converting between strings and numbers.
Example
#include <iostream>
#include <string>
using namespace std;
int main() {
// Input with spaces
string fullName;
cout << "Enter full name: ";
getline(cin, fullName);
// String to number
string numStr = "42";
int num = stoi(numStr); // string to int
double d = stod("3.14"); // string to double
// Number to string
string s = to_string(42); // "42"
string s2 = to_string(3.14); // "3.140000"
return 0;
}