C++ - Strings: Concatenation

Overview

Estimated time: 15–25 minutes

Combine strings using +, +=, and append. Learn how to safely mix string literals and std::string values.

Learning Objectives

• Concatenate std::string values and literals.
• Know when to convert C-strings explicitly.

Prerequisites

• C++ - Strings (Basics)

Examples

#include <string>
#include <iostream>
int main(){
  std::string a = "Hello";
  std::string b = a + ", " + "world"; // literal + string is fine if one side is std::string
  std::string c = a; c += "!";
  std::string d; d.append("Hi");
  std::cout << b << "\n" << c << "\n" << d << "\n";
}

Common Pitfalls

• "a" + "b" does not concatenate C string literals (it performs pointer arithmetic); ensure a std::string is involved: std::string("a") + "b".