[SOLVED] Variable problem - any ideas?

[Chappers]

Hi, just a quickie. This works, so I can get as many error/success messages as I want during a script, then have them all print out wherever I want them to:

 

<?php
if (empty($example)) {
$msgs[] = "Example did not work";}
else {
$msgs[] = "Example worked";}

if (empty($another)) {
$msgs[] = "Another did not work";}
else {
$msgs[] = "Another worked";}

foreach ($msgs as $message) {
echo "$message<br>";}

 

So in a certain section I get all messages printed one after another. No problem. But if I need to add the name of a variable which was involved to $msgs[], so I know exactly what it's referring to, like this:

 

<?php
if (empty($example)) {
$msgs[] = "Example did not work";}
else {
$msgs[] = "Example worked";}

if (empty($another)) {
$msgs[] = "$another did not work";}
else {
$msgs[] = "$another worked";}

foreach ($msgs as $message) {
echo "$message<br>";}

 

The code fails with an error regarding the square brackets. Is there a way I can do it this way but have $msgs[] = "Blah blah $variable blah blah"; and have it work?

 

Thanks!

[xtopolis]

Use single quotes when you don't want the variable name to be interpreted.

[Chappers]

Oh, I do want the variable name to be interpreted. I want $another from my example to be entered into $msgs[] as the string it originally was, but either way, it produces an error. I've tried:

<?php
$msgs[] = "This $example failed";
$msgs[] = "This ".$example." failed";
$msgs[] = "This '$example' failed";
$msgs[] = "This {$example} failed";
$msgs[] = $example;
?>

 

And all create a parse error: Parse error:  parse error, unexpected ']', expecting T_STRING or T_VARIABLE or T_NUM_STRING

[xtopolis]

$msgs[] = 'This $example succeeded.';

[.josh]

none of those should have failed. Your error is somewhere else.

[Chappers]

You are, of course, absolutely right - the problem was elsewhere. The syntax checker I use online was correctly finding an issue, but wrongly stating what the issue was, as it sometimes does (but it's good overall to find errors). I would have realised if perhaps I hadn't been doing this at 3am... For others who might search and find this I'll explain:

 

I was using this snippet of code from a much larger page:

 

<?php
$result = mysql_query("DROP TABLE $table");
if (mysql_error()) {
$errmsg = "<span class='error'>Query failed.<br>MySQL Error Number: ".mysql_errno()."<br>MySQL Error Description: ".mysql_error()."</span>";
echo $errmsg;
}

else {
echo "Table $table deleted";
}
?>

 

That worked fine, until I changed it to use an array so that I can print all error/success messages afterwards on a specific area of the page. I removed the <span class...> from the error message as I could add a class to the whole contents of the $msgs[] array myself before printing it. My test code was:

 

<?php
$result = mysql_query("DROP TABLE $table");
if (mysql_error()) {
$msgs[] = "Query failed.<br>MySQL Error Number: ".mysql_errno()."<br>MySQL Error Description: ".mysql_error().";
}

else {
$msgs[] = "Table $table deleted";
}

foreach ($msgs as $message) {
echo $message;
}?>

 

It was the code above that wasn't working, creating an error wrongly attributed to the $msgs[] square bracket. It was my lack of understanding about the correct format to use when mixing normal words and functions, if that's how to describe it. It was this:

 

<?php
// Below is the incorrect line, only one double-quotes at the end of it.
$msgs[] = "Error inserting data.<br>MySQL Error Number: ".mysql_errno()."<br>MySQL Error Description: ".mysql_error().";

// This one works
$msgs[] = "Error inserting data.<br>MySQL Error Number: ".mysql_errno()."<br>MySQL Error Description: ".mysql_error()."";
?>

 

So, trouble started when I removed the span class attribute because I didn't realise that when I removed the </span> at the end, I needed to leave the extra set of double quotes. I still don't properly get the business of functions and words mixed together and using "." to switch between the two, but it's working now anyway.

[xtopolis]

http://us.php.net/types.string

 

The jist of it is:

Single quotes are straight 'display what is there, but do not try to change anything'

echo 'I like php.';
// I like php
echo 'I like $php.';
// I like $php

 

Double quotes are for interpretations, where it tries to "find the value"

$php = 'cats';
echo "I like php.";
// I like php
echo "I like $php.";
// I like cats

the "." (dot) operator is used for concatenation - the joining of strings

$str = 'I like ';
$str2 = 'elephants.'
echo $str . $str2;
// I like elephants.

[Chappers]

That's very helpful, thanks a lot. I didn't know those things, so it'll help me understand why my code sometimes does unexpected things.