String concantenation error 1

maharg · Dec 4, 2004

Hi

I'm new to PHP and can't seem to get my syntax right here.

This little test code should print out as ....

1,2,3,4,5,6,Graham,
2,4,6,8,10,12,Edward,
10,20,30,40,50,60,James,
41,42,43,44,45,46,Gordon,

But it doesnt.

My error is in the line print_r($person$n[$i]);
to do with how I'm concantenating $person and $n

Can anyone help me find a solution?

Thanks in advance!!

Graham

Code:

<html>
<body>
   
<?php

$person1 = array(1,2,3,4,5,6, "Graham");
$person2 = array(2,4,6,8,10,12, "Edward");
$person3 = array(10,20,30,40,50,60, "James");
$person4 = array(41,42,43,44,45,46, "Gordon");

$n=1;
while($n<=4){

       $i=0;
       while($i<=6)
       {
       print_r($person$n[$i]);
       echo ",";
       $i++;
        }
       
echo "<br />";
$n++;}
?>

</body>
</html>

kenrbnsn · Dec 4, 2004

To join two strings use the period "."

In your case, you should simplify your code to use a multi-dimensioned array and the implode function to format your output.

Code:

<?php

$people = array(array(1,2,3,4,5,6, "Graham"),
          array(2,4,6,8,10,12, "Edward"),
          array(10,20,30,40,50,60, "James"),
          array(41,42,43,44,45,46, "Gordon"));

for ($n=0;$n<count($people);$n++)
       echo implode(',',$people[$n]).",<br />\n";
?>

Ken

maharg · Dec 4, 2004

Hi Ken,

Wow, that's more efficient, thanks!

I tried the "." period string addition in my example but it wouldn't work. It works fine for other strings, and I use it a lot.

But, keeping the basic structure of my code example, how would you combine $person and $n so that the code understands ...
$person1 $person2 etc?

Just so I can understand where my syntax was wrong in that line, keeping all else the same.

I'm off to read about multidimensioned arrays now...

Thanks again Ken

kenrbnsn · Dec 4, 2004

What you want to do is create a variable with the value of "person1", "person2", etc. and then use that value as your variable. Look up variable variables on

http://www.php.net/

The following code

Code:

<?
$person1 = array(1,2,3);
$person2 = array(4,5,6);
$per = 'person';
for ($i=1;$i<3;$i++) {
    $perx = $per .$i;
    echo $perx,': ' ,implode(',',$$perx),"\n"; }
?>

will print

Code:

person1: 1,2,3
person2: 4,5,6

Basically, two '$' preceding a variable name say take the value of the variable and used it as a variable name.

Ken

maharg · Dec 4, 2004

Ken, that's great, thanks for everything.
Much appreciated.

Best regards,

Graham

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String concantenation error 1

maharg

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kenrbnsn

Technical User

maharg

Technical User

kenrbnsn

Technical User

maharg

Technical User

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