function "printf" declared implicitly

The "printf" function is a standard library function in C programming language used to print formatted output to the console or a file. It is declared in the "stdio.h" header file, and it is not implicitly declared by the compiler, which means that you need to include the "stdio.h" header file explicitly in your program to use the "printf" function.

For example, the following code snippet demonstrates how to use the "printf" function to print a string to the console:

#include <stdio.h>

int main() {
   printf("Hello, world!\n");
   return 0;
}

In this example, we include the "stdio.h" header file, which contains the declaration of the "printf" function. We then call the "printf" function to print the string "Hello, world!" to the console, followed by a newline character (\n). Finally, we return 0 to indicate that the program has executed successfully.