How to append strings using sprintf?

In C programming, the sprintf function is commonly used to write formatted data into a string. If you need to use sprintf to append strings, you can use the current length of the string as the starting position to append new content to the end of the existing string.

Here is a specific example demonstrating how to use sprintf to append strings:

c
#include <stdio.h>
#include <string.h>

int main() {
    char str[100] = "Initial text";

    // Current length of the string
    int len = strlen(str);

    // Using sprintf to append strings
    sprintf(str + len, ", this is appended text");

    printf("Final string is: %s\n", str);

    return 0;
}

In this example:

• A sufficiently large character array str is first defined and initialized to "Initial text".
• By using strlen(str), we obtain the current length of the string, which indicates where the string ends in memory.
• The line sprintf(str + len, ", this is appended text") writes from the len position of the array, which is exactly the end of the original string. This approach appends new content to the end of the original string without overwriting existing content.

This method is simple and effective, particularly suitable for scenarios requiring dynamic string construction.