For functions you don’t use all the time, you might forget what the parameters are, or in which sequence they are to be given. At least I do. The editors mentioned above have a feature where it can suggest a function on the go. So does Notepad++. But (afaik) Zend and Dreamweaver also suggest the parameters. Which N++ does not.

The ‘api’ for N++ lacks the parameter suggestion. But I wrote a little script which added the parameters to the file.

You can download a copy of php.api here.(use ‘save target as’)

Please note that using the suggestion will result in the description text of the parameters to be added as well. So for now, just use the suggestions as guidance.

To use this file i suggest to set the following settings:
auto-completion enabled on function, starting from 2 charatures (or it will drive you insane with spaces and tabs)

Also, as a tip, you can use Ctrl+shift+space to complete variables in your file.

[edit]
More posts about Notepad++ can be found here: Notepad++ customization.