Pseudo type in PHP

: This article mainly introduces the pseudo type in PHP. if you are interested in the PHP Tutorial, refer to it. 1. mixed

Mixed indicates that a parameter can accept multiple (but not necessarily all) types.

For example, gettype () can accept all PHP types.
2. number
Number indicates that a parameter can be integer or float.

3. callback

Same as callable usage after PHP 5.4
4. void

Void as the return type means that the return value of the function is useless.

Void as the parameter list means that the function does not accept any parameters.

5. "..."

In the function prototype, $... indicates and so on.

This variable name is used when a function can accept any parameter.

The above describes the pseudo-type in PHP, including some content, and hope to help those who are interested in the PHP Tutorial.