[RESOLVED] Notice: Undefined offset:

[mrs]

Hi, I am trying to work my way through a book teaching myself php, mysql etc etc..... i keep getting this notice....

Notice: Undefined offset: 3 in C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\email\output_fns.php on line 320

line 320 reads

if ($button[$i])display_button($button[$i], $extra_parameters);

What i have found is that if i put a @ sign infront of the $button (as in @$button) it clears the notice.

Its probably totally clear whats wrong, but I cant see it.

Any advice please??

Many thanks

Mrs

[cahva]

Error means that the index 3 in $button doesnt exist($button[3]). You should always check that variables and indexes exist before using them. Dont use @ sign as that only suppresses the error, not corrects the problem.

The right way to check if something exists is to use isset function:

if (isset($button[$i])) display_button($button[$i], $extra_parameters);

[mrs]

Many thanks for replying.

It just strikes me as strange .... as a complete newbie I am copying this code from a book! (php and mysql web development) inc cd with all source codes on it. How come the coding is wrong?

Anyway thank you for answering. Deflated I shall resume :queasy:

[cahva]

If its an old book, it will have things like that. In "the bad old times" it was common to use variables without checking them first, register globals was set to on and things like that..

It's mainly PHP's fault that it lets you use variables without defining them first. Many other languages would throw you fatal error for undefined variables.

The easy way out would be to lower the error reporting not show notice errors but keep them on and you'll quickly start to define variables automatically and be a better coder 🙂

[mrs]

thanks cahva

its not that old a book, the next edition isnt out yet and it was recommended by a php programmer of 15yrs.

I will look into what you have suggested and thank you very much for the advice.

cheers
Mrs