Problem with custom functions

[748323]

I tried creating my own function that will reverse a string. I know I can use strrev(); but that's not fun, and it doesn't teach me anything

<?

function reverse_string($string, $var2) {
$str_len = strlen($string);
for($i = $str_len; $i >= 0; $i--) {
$var2 .= $string{$i};
}
}

reverse_string("1234567890", $new_string);
echo $newstring;

?>

When I try to echo $newstring, nothing comes up. What am I doing wrong?

 

[Vragabond]

Is $new_string supposed to be the same as $newstring? Have you tried return?

function reverse_string($string)
{
  $str_len = strlen($string);
  for($i = $str_len; $i >= 0; $i--)
  {
    $var2 .= $string{$i};
  }
  return $var2
}

echo reverse_string("1234567890");

 

[748323]

I don't want the function to reverse the string. I want it to reverse it, and then place it in the variable indicated in the second parameter of the custom function.

I will try the $new_string thing. What a stupid mistake of me to take

 

[748323]

<?

function reverse_string($string, $var2) {
$str_len = strlen($string);
for($i = $str_len; $i >= 0; $i--) {
$var2 .= $string{$i};
}
}

reverse_string("1234567890", $newstring);
echo $newstring;

?>

Still didn't work

 

[Vragabond]

How about

$newstring = reverse_string("1234567890");

on my code. The way you're doing it cannot work, because variables in the function are not available outside that function.

 

[748323]

What if I use

 global $var2

?

 

[748323]

<?

function reverse_string($string) {
$str_len = strlen($string);
for($i = $str_len; $i >= 0; $i--) {
$var2 .= $string{$i};
}
return $var2;
}

$newstring = reverse_string("123456789");
echo $newstring;

?>

Okay. Thanks. That's all I could come up with. I didn't know that variables in a function are only used for that function!

 

[ericbrunson]

Try googling for "php parameter function reference" or look up what the & operator does to a function parameter. The key phrase you're looking for is "pass by reference".