How do you concatenate strings in C?

In C, concatenating strings is done using the strcat() function, which is part of the standard string handling library (string.h). The strcat() function takes two parameters: the destination string and the source string. It appends the source string to the end of the destination string, modifying the destination string in place. It automatically adds a null terminator to indicate the end of the concatenated string.

This function is specifically designed for string manipulation in C, making it suitable for the task of combining two strings into one. It is essential to ensure that the destination string has enough allocated space to hold the additional characters from the source string, including the null terminator.

In contrast, other functions mentioned do not serve the purpose of concatenating strings. The strcpy() function is used for copying strings from a source to a destination, which is fundamentally different from concatenation. The functions join() and merge() are not part of the standard C library and are generally not used in C programming for string operations.