This function is used to write a formatted string to a specified output stream.

    fprintf(resource,format, args)

In the above syntax "resource" specifies where to output, "format" specifies the formatting to be used, "args" specifies the arguments passed.

The following are some of the parameters of "format" option used in this function

Usually in the "fprintf" function based on the "%" the arguments are displayed accordingly

    <?php
    $str = "Hi";
    $num = 456;
    $file = fopen("test.txt","w");
    echo fprintf($file,"%s how are you. I owe you %u" rupees,$str,$num);
    ?>

    Hi how are you, I owe you 456 rupees 

In the above example the arguments "$str", "$num" will be added to the string based on the formatting specified, the output is added to the file "file.txt"