运行 ❯
获取您自己的
PHP
服务器
×
更改方向
更改主题，深色/浅色
转到 Spaces
<!DOCTYPE html> <html> <body> <p>The parameter "mode 4" will return a string with all the unused characters. In this example, the characters not used in "Hello World!" are:</p> <?php $str = "Hello World!"; echo count_chars($str,4); ?> </body> </html>
