Doctrine\MongoDB\Aggregation\Stage\Operator::toLower PHP Method

The argument can be any expression as long as it resolves to a string.

See also: http://docs.mongodb.org/manual/reference/operator/aggregation/toLower/

See also: Expr::toLower

public toLower ( mixed \| Expr $expression )
$expression	mixed \| Doctrine\MongoDB\Aggregation\Expr

    public function toLower($expression)
    {
        $this->expr->toLower($expression);
        return $this;
    }

Operator