How can I write a file in UTF-8 format?

To write a file in UTF-8 encoding with PHP, you can use the fopen, fwrite, and fclose functions. Here is an example of how you can use these functions to write a string to a file in UTF-8 encoding:

<?php

$str = "Hello, world!";

$file = fopen("output.txt", "w");

fwrite($file, $str);

fclose($file);

This will create a new file called "output.txt" and write the string "Hello, world!" to it. The file will be saved in UTF-8 encoding.

If you want to specify the encoding when you create the file, you can use the utf8_encode function to convert the string to UTF-8 encoding before writing it to the file. Here is an example:

<?php

$str = "Hello, world!";

$file = fopen("output.txt", "w");

fwrite($file, utf8_encode($str));

fclose($file);

This will create a new file called "output.txt" and write the string "Hello, world!" to it, using UTF-8 encoding.