variable used later in code?

[galvin]

I have code at the top of my page like this...

 

$N = "<td class='num'>$i</td>";

 

Then later on, I have code like this snippet below.  But this code doesn't seem to be doing what I want (i.e. the $i variable doesn't seem to be respected).

 

So is something wrong with structuring things this way?  I'm trying to store repeatable code up top just once (since I use it A LOT) and then use it where needed  using this code below, but something isn't right with it. 

 

for ($i=1; $i<=8;$i++) {
echo "<tr>" . $N . "</tr>";
}	

 

FYI, it's outputting nothing where $i is.  So in all 8 instances, it's outputting this..

 

<tr><td class='num'></td><tr>

 

Any thoughts?

[Alex]

Simply put, it doesn't work that way. The string, $N, will be assigned a value where it's declared including the value of $i, nothing.

[Psycho]

That is because at the time that you define $N, the $i variable is either not defined or an empty string. When you define a string using double quotes, the string is defined using the values of the variables at the time you define it. The PHP parser has no clue that you plan to use a different value later on. Try this:

$N = "<td class='num'>[i_VAR]</td>";

for ($i=1; $i<=8;$i++)
{
    echo "<tr>" . str_replace("[i_VAR]", $i,  $N) . "</tr>";
}

[PFMaBiSmAd]

Or you could write a function that would accept and operate on the current value at the time the function is called.

[galvin]

PFMaBiSmAd, is writing a function the better option in your opinion?  I have a ton of code where "$i" was in the repeatable code at the top of my pages, so doing mjdamato's solution (which works, thanks!) will require a lot of str_replace's in my code.  Although, now that I say that, I guess any function I create will need to contain a str_replace anyway.

 

Anyway, just curious which method you think is better before I embark on updating all of my code

[PFMaBiSmAd]

I'm not sure how 'real' your example is, but a function would be used like this -

 

<?php

function td_class_num($i){
return "<td class='num'>$i</td>";
}

for ($i=1; $i<=8;$i++) {
echo "<tr>" . td_class_num($i) . "</tr>";
}
?>

[galvin]

If I have "$i" acting as an index in an array, and I want that to get replaced via mjdamato's solution using [i_VAR], how would I write it. Below is not correct.  Yes, I sometimes get really confused with all the brackets and quotes and whatnot

 

if ($alldata['[i_VAR]']['image'] == "")

 

In other words, I had this code to start...

 

if ($alldata['$i']['image'] == "")

 

...but now want to implement mjdamato's solution,  how would I rewrite it with [i_VAR] so that all the quotes and brackets are accurate?

 

I'm still not sure if I'm going the route of a function or the [i_VAR] solution, but just trying to clear this up regardless

[PFMaBiSmAd]

Your last question has nothing really to do with the first question and the solutions already posted (unless you are trying to make a template system that has embedded conditional logic in it, in which case you wouldn't do it this way at all.)

 

The [i_VAR] is simply a unique place holder/tag that you make up and put into a STRING at the point where you want to substitute/replace it with an actual value when the code is executed.

 

Your if ($alldata[$i]['image'] == "") code isn't the same situation, because it is not a string you are trying to replace values in. It's an array that expects array index values to address the elements of the array.

[galvin]

Ok, makes perfect sense, thanks for explaining!