framework/web/ErrorAction.php
protected function getExceptionName()
    {
        if ($this->exception instanceof Exception) {
            $name = $this->exception->getName();
        } else {
            $name = $this->defaultName;
        }

        if ($code = $this->getExceptionCode()) {
            $name .= " (#$code)";
        }

        return $name;
    }
protected function getExceptionName()
    {
        if ($this->exception instanceof Exception) {
            $name = $this->exception->getName();
        } else {
            $name = $this->defaultName;
        }

        if ($code = $this->getExceptionCode()) {
            $name .= " (#$code)";
        }

        return $name;
    }
Returns the exception name, followed by the code (if present).

@return string
@since 2.0.11