Output from functions - frowned upon?

ukjoe

I've been using PHP basically for a while now, but just starting to get up to date with OOP in PHP5 really.

One question I have is regarding functions as I'm starting to use them more and more. I seem to have it in my head that functions should not output directly to the screen, e.g. using echo, print etc, but should always just return what ever value to where the function was called from.

I'm now trying to setup some basic classes for use on my site, and want a pageBuilder class that generates valid page html headers and footers.

I can see two ways of doing this:
1) echo all the out put from the function, a line at a time
2) build up a pageHeader variable within the function, and then just return this one variable at the end of the function.

Anybody got any thoughts on this?

Thanks in advance for any help 🙂

laserlight

I seem to have it in my head that functions should not output directly to the screen, e.g. using echo, print etc, but should always just return what ever value to where the function was called from.

That's usually good practice. One advantage is that it is more flexible, e.g., the caller could write the return value to a file instead of printing it out.

I'm now trying to setup some basic classes for use on my site, and want a pageBuilder class that generates valid page html headers and footers.

I can see two ways of doing this:
1) echo all the out put from the function, a line at a time
2) build up a pageHeader variable within the function, and then just return this one variable at the end of the function.

Anybody got any thoughts on this?

In this case, the pageBuilder class seems to be intended to print output, so printing to screen is fine. To make this clear you could name the function printPageHeader() instead.

ukjoe

Cheers for reply and info, laserlight. Sometimes hard to find these things out as books assume you already know, and many web pages just gloss over this information with the same assumption I guess. Ty!