Example: String Concatenation in C

// String Concatenation
#include <stdio.h>
#include <string.h> // Required for strcat()

int main() {
    // Step 1: Declare destination and source strings
    char destination[50] = "Hello"; // Must be large enough for combined string
    char source[] = ", World!";

    // Step 2: Print initial destination string
    printf("Initial Destination: \"%s\"\n", destination);

    // Step 3: Use strcat() to append source to destination
    strcat(destination, source);

    // Step 4: Print the concatenated string
    printf("Concatenated String: \"%s\"\n", destination);

    // Example with strncat for safety
    char sentence[50] = "This is a ";
    char fragment[] = "short sentence that is still quite long.";

    printf("\nSafe Concatenation Example:\n");
    printf("Initial sentence: \"%s\"\n", sentence);

    // Calculate remaining space: sizeof(sentence) - strlen(sentence) - 1
    // -1 for the null terminator that strncat will add
    strncat(sentence, fragment, sizeof(sentence) - strlen(sentence) - 1);

    printf("Concatenated sentence: \"%s\"\n", sentence);

    return 0;
}