What is the reason why thinkphp means judging 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!

Reply content:

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!

In case you just wrote an equal sign and don’t know it yet.

This should be just a personal habit and has no impact at all

If you write it backwards, if you write an =, an error will be reported directly. If you write it forward, it will assign a value and no error will be reported. It is mainly to prevent errors

Abnormal writing method, as mentioned on the first floor, prevent missing a "=" sign, otherwise an error will be reported

A good coding habit. If the comparison is written as $name='a', this expression is to assign the value a to $name. If 'a'=$name, it will not

If you have time, you can read the book "C Traps and Defects".