Error I can't explain.

[aspen]

Error Code:

Parse error: parse error, expecting `T_VARIABLE' or `'$'' in /home/mynacfa/public_html/plans1.php on line 49

Code Segment: Line 49 marked by asterisks

    while($main = mysql_fetch_array($get_data)){  
        $i_EFC_f = $main[i_EFC_f]; 
        $i_EFC_i = $main[i_EFC_i]; 
        $a_EFC_f = $main[a_EFC_f]; 
        $a_EFC_i = $main[a_EFC_i]; 
        $ann_f = $main[ann_f]; 
        $ann_i = $main[ann_i]; 
        $4_f = $main[4_f];  *******
        $4_i = $main[4_i];
        $pb_1 = $main[pb_1];
        $pb_2 = $main[pb_2];
    } 

So I got no idea whatsoever. I really don't see the problem. This isn't one of those stupid "Can't name a variable starting with a number" rules like in javascript is it? The information had to be submitting with php and that went off fine using the same variable names.

[freakysid]

Variable names cannot start with numbers. I'm pretty sure this is the case with many languages (Java, C, C++, etc).

[aspen]

Yup, that was it.... I hate that rule. It always used to mess me up in js, I didn't know it was a rule in php too.

[freakysid]

As this rule applies to every programming language I have used (except VB - I can't say that I know whether it applies to VB) - there must be some reason for this. There must be some underlying computer architecture reason for why a compiler will not accept a variable who's name begins with a digit. It would be interesting to know why this is.

<<edited>>

This page gives a hint: http://www.ladysharrow.ndirect.co.uk.../chapter_2.htm

             1 When the assembler looks at something it needs to know
             whether it is a name or a number. Is 'A7' a name or a hex number?
             Is '3D' a name or a number? To solve this problem, all assemblers
             and all compilers insist that -> if the first character is a
             number, it's a number; if the first character is not a number, it
             is not a number. That is why you can't start a variable name with
             a number.

And the flip-side to this is that hex numbers must start with a numeral:

 4. A hex number. A hex number must start with a number, so if the
             highest digit is A - F, there must be a 0 in front.{1} b77h is
             illegal, 0b77h is legal.

I learn something every day

[aspen]

in something like js without a variable identifier I can see it perhaps. But I don't see why it can't recognize the variable identifier ($) and realize that what comes after that is a variable name.

[freakysid]

It is an interesting question. I remember reading in an faq or in the man or somewhere that PHP was originally written in Perl, but I am assuming that since version 3, the PHP interpreter (the "Zend Engine") is written in C. I'm guessing at that because there seems to be a lot of the C API and standard libraries showing through in PHP. I'm guessing that PHP is just throwing some thin wrappers around C standard functions. So this may explain why PHP follows the C rules with naming variables. It would be interesting to know more about this.