str_replace function str_replace is a string function that replaces occurrences of a substring with another substring. Syntax : str_replace(find, replace, string, count) Parameters: -find: The substring to search for. -replace: The substring to replace with. -string: The original string. -count(optional): The number of replacements made. Example: $string = "Hello, welcome world!"; $new_string = str_replace("world", "universe", $string); echo $new_string; // Output: "Hello, universe!" strlen() fnction is a PHP function that returns the length of a string. Syntax: strlen(string) Parameter: -string: The input string Return Value: The length of the string (integer). Example: $string = "Hello, World!"; $length = strlen($string); echo $length; // Output: 13 [Google Ads] PHP->IMAGE UPLOAD : (UPLOAD IMAGES using Move upload function) $image_file1 = $_FILES['file']['name']; $c1 = ran...