What does extends followed by \XXX mean in php?

Question

for example:

class SendSmsRequest extends \RpcAcsRequest{}

What does \ here mean?

Answer 1

The meaning of top-level namespace.

You can take a look at the php documentation. http://php.net/manual/en/lang...

Answer 2

In PHP, the first few slashes of xxxxxxxxxxxx represent the namespace, and the last one xxxx represents the variables, classes, etc. in the namespace
The first slash represents the top-level domain name space, which can be omitted, so it is generally For variables or classes in the top-level domain name space, write directly $xxx or XXXX.

PHP documentation:
Global namespace: http://php.net/manual/en/lang...
Namespace: http://php.net/manual/en/lang...