需求之间的差异，包括，需求一次，包括一次？

Question

In PHP:

• When should I use require vs. include?
• When should I use require_once vs. include_once?

转载于:https://stackoverflow.com/questions/2418473/difference-between-require-include-require-once-and-include-once

Answer 1

There are require and include_once as well.

So your question should be...

1. When should I use require vs. include?
2. When should I use require_once vs. require

The answer to 1 is described here.

The require() function is identical to include(), except that it handles errors differently. If an error occurs, the include() function generates a warning, but the script will continue execution. The require() generates a fatal error, and the script will stop.

The answer to 2 can be found here.

The require_once() statement is identical to require() except PHP will check if the file has already been included, and if so, not include (require) it again.