src/StringBuilder.php
public function reverse()
    {
        $length   = $this->length();
        $reversed = '';
        while ($length-- > 0) {
            $reversed .= mb_substr($this->string, $length, 1, $this->encoding);
        }

        $this->string = $reversed;
        return $this;
    }
public function reverse()
    {
        $length   = $this->length();
        $reversed = '';
        while ($length-- > 0) {
            $reversed .= mb_substr($this->string, $length, 1, $this->encoding);
        }

        $this->string = $reversed;
        return $this;
    }
Reverse the sequence.

@return StringBuilder