What is the reason why php equals judgment and writing in reverse?

When I looked at thinkPHP source code recently, I saw that some judgment methods are written in reverse, for example:

<code>if(''==$name) { // 获取全部变量
        $data       =   $input;
        $filters    =   isset($filter)?$filter:C('DEFAULT_FILTER');
        if($filters) {
            if(is_string($filters)){
                $filters    =   explode(',',$filters);
            }
            foreach($filters as $filter){
                $data   =   array_map_recursive($filter,$data); // 参数过滤
            }
        }
    }</code>

Xiaobai, please explain why it is ''==$name instead of $name ==''?
What is the difference between the two?
Thank you!