This is a collection of questions that come up every now and then about syntax in PHP. This is also a Community Wiki, so everyone is invited to participate in maintaining this list.
It used to be hard to find questions about operators and other syntax tokens.¹
The main idea is to have links to existing questions on Stack Overflow, so it's easier for us to reference them, not to copy over content from …
PHP中有哪些?和:运算符？
例如:
(($request_type == 'SSL') ? HTTPS_SERVER : HTTP_SERVER)