Online PHP editor | output for j1qXn

<?php trait StringFunctionMapper { public Closure $substr; protected ?string $encoding = null; public function setSingleByte(): void { $this->encoding = null; $this->substr = fn (string $string, int $start) => substr($string, $start); } public function setMultiByte(string $encoding = 'UTF-8'): void { $this->encoding = $encoding; $this->substr = fn (string $string, int $start, int $length = null) => mb_substr($string, $start, $length, $this->encoding); } } $temp = new class () { use StringFunctionMapper; }; $temp->setSingleByte(); var_dump(substr("search phrase", 6), ($temp->substr)("search phrase", 6)); $temp->setMultiByte(); var_dump(mb_substr("search phrase", 6), ($temp->substr)("search phrase", 6));