C++ String Concatenation

String concatenation means joining two or more strings together. In C++, you can concatenate strings using the std::string class or C-style character arrays.

1. Using + Operator (std::string)

The + operator is the easiest way to concatenate std::string objects.

#include <iostream>
#include <string>
using namespace std;

int main() {
    string firstName = "John";
    string lastName = "Doe";

    string fullName = firstName + " " + lastName;
    cout << "Full Name: " << fullName;

    return 0;
}

2. Using append() Function

The append() function adds text to the end of a string.

#include <iostream>
#include <string>
using namespace std;

int main() {
    string str = "Hello";
    str.append(" World");

    cout << str;
    return 0;
}

3. Using strcat() (C-Style Strings)

For C-style strings, the strcat() function from is used. Ensure the destination array has enough space.

#include <iostream>
#include <cstring>
using namespace std;

int main() {
    char str1[20] = "Hello";
    char str2[] = " World";

    strcat(str1, str2);
    cout << str1;

    return 0;
}

4. Important Notes

1. The + operator works only with std::string objects. 2. append() modifies the original string. 3. For C-style strings, always allocate sufficient memory before using strcat(). 4. Prefer std::string for safer and easier string manipulation.

Conclusion

C++ provides multiple ways to concatenate strings. The std::string class offers the safest and most convenient approach, while C-style string concatenation requires careful memory management.