HELP Create a dynamic variable by joining two together PHP 5

[Alex C]

Hi,

 

Sorry if this seems simple but I am going a bit mad. I have done this a thousand of times before and for some reason today it is not working.

 

I just want to join two variables together like $item_number$i

 

But for some reason it just wont work it only ever prints out the value of $i

 

I swear the following used to work in PHP 4

 

I am using php 5

 

$item_number1 = "foo";
$item_number2 = "bar";

$i = 1;
while($i <= 2) {
echo "$item_number$i <br />";
$i++;
}

 

The above code just prints out:

 

1

2

 

Please can someone help, I am going insane

 

Thanks

[premiso]

I would suggest using an associative indexed array instead, but here is how you would achieve that:

 

$item_number1 = "foo";
$item_number2 = "bar";

$i = 1;
while($i <= 2) {
   echo ${$item_number . $i} . "<br />";
   $i++;
}

 

Should do what you want. An array would be better a quicker, however. As an FYI.

[Alex C]

Hi premiso

 

Thanks for the quick reply, for some reason the following code doesn't print out anything

 

$item_number1 = "foo";
$item_number2 = "bar";

$i = 1;
while($i <= 2) {
   echo ${$item_number . $i} . "<br />";
   $i++;
}

 

Have you any ideas?

 

Can I ask is this a change in PHP 5 that has stopped the usual "$var$i" from working as its been bugging me all day.

[kenrbnsn]

Try:

<?php
$item_number1 = "foo";
$item_number2 = "bar";

$i = 1;
while($i <= 2) {
   echo ${'item_number' . $i} . "<br />";
   $i++;
}
?>

 

Ken

[Alex C]

Thanks kenrbnsn that works perfectly.

 

Out of interest I have decided to use the array method as previously mentioned, this is a faster better technique?

 

$item_number[1] = "foo";
$item_number[2] = "bar";

$i = 1;
while($i <= 2) {
   echo $item_number[$i] . "<br />";
   $i++;
}

[kenrbnsn]

If you're going to use an array, I would suggest using either a for loop

<?php
$item_number = array(1=>'foo',2=>'bar');
for ($i=1;$i<3;++$i) {
   echo $item_number[$i] . "<br />\n";
}?>

or a foreach loop

<?php
$item_number = array(1=>'foo',2=>'bar');
foreach ($item_number as $val) {
   echo $val . "<br />\n";
}
?>

 

Ken

[PFMaBiSmAd]

I have seen benchmarks that indicate that using an array is 3x faster than using variable variables.

[Alex C]

Thanks for the great feedback guys, I always think its good to try and code to the best standards. I will implement this technique straight away.

 

Thanks again