problem with multiple conditions

[greedo]

Hi, first of all, please bear with me, I don't really know a great deal
about php programming, as will be painfully obvious from the code
snippet I'm gonna post. But I need this problem solved, and I can't
find the information I need (or maybe I can't understand it). So here's
the thing:

What I have is a range of integers, and I need those whose digits
alternate between odd and even. Example: 123456789. For that purpose I
have this thingy here:

settype($zee, "string");
if (($zee[0] % 2 != 0) && ($zee[1] % 2 == 0))
{
echo $zee . "<br />";

}

Just to be precise: I want to have $zee echoed, if the first digit is
odd and the second is even.

Now, this doesn't work, because apparently the second condition is
never true. I don't get why. Because if I change the "==" in the second
condition to "!=" (that is to say I want both digits to be odd), then
it works fine! Can someone help me fix this?

PS:
When the conditions are put like this:
if (($zee[0] & 1) && ($zee[1] & 0))
the exact same thing happens: it works with two odd conditions, but not
with one odd, one even.

[Mladen Gogala]

On Sun, 26 Nov 2006 07:44:53 -0800, greedo wrote:

Hi, first of all, please bear with me, I don't really know a great deal
about php programming, as will be painfully obvious from the code
snippet I'm gonna post. But I need this problem solved, and I can't
find the information I need (or maybe I can't understand it). So here's
the thing:

What I have is a range of integers, and I need those whose digits
alternate between odd and even. Example: 123456789. For that purpose I
have this thingy here:

settype($zee, "string");
if (($zee[0] % 2 != 0) && ($zee[1] % 2 == 0))
{
echo $zee . "<br />";

}

Just to be precise: I want to have $zee echoed, if the first digit is
odd and the second is even.

Now, this doesn't work, because apparently the second condition is
never true. I don't get why. Because if I change the "==" in the second
condition to "!=" (that is to say I want both digits to be odd), then
it works fine! Can someone help me fix this?

PS:
When the conditions are put like this:
if (($zee[0] & 1) && ($zee[1] & 0))
the exact same thing happens: it works with two odd conditions, but not
with one odd, one even.

Your type conversion is a mortal sin and may cost you dearly when you meet
the Great Programmer. Repent, o sinner, change thy evil ways and do
something like this:

$zere="345678";
$zee=preg_split('//',$zere,-1,PREG_SPLIT_NO_EMPTY);
if (($zee[0] % 2 != 0) && ($zee[1] % 2 == 0))
{
echo "zere=$zere\n";

}
else echo '$zee[0]=',$zee[0]," ",'$zee[1]=',$zee[1],"\n";
BTW, your assumption about C-ish equivalent between strings and arrays
does not hold water in the PHP world. Your "settype" trick would be neat,
had it worked.

--
http://www.mladen-gogala.com

[greedo]

First of all thanks, I will try to figure out what you did there and
hopefully this'll do. May take me a moment, tho. :)

Mladen Gogala wrote:

On Sun, 26 Nov 2006 07:44:53 -0800, greedo wrote:

Hi, first of all, please bear with me, I don't really know a great deal
about php programming, as will be painfully obvious from the code
snippet I'm gonna post. But I need this problem solved, and I can't
find the information I need (or maybe I can't understand it). So here's
the thing:

What I have is a range of integers, and I need those whose digits
alternate between odd and even. Example: 123456789. For that purpose I
have this thingy here:

settype($zee, "string");
if (($zee[0] % 2 != 0) && ($zee[1] % 2 == 0))
{
echo $zee . "<br />";

}

Just to be precise: I want to have $zee echoed, if the first digit is
odd and the second is even.

Now, this doesn't work, because apparently the second condition is
never true. I don't get why. Because if I change the "==" in the second
condition to "!=" (that is to say I want both digits to be odd), then
it works fine! Can someone help me fix this?

PS:
When the conditions are put like this:
if (($zee[0] & 1) && ($zee[1] & 0))
the exact same thing happens: it works with two odd conditions, but not
with one odd, one even.

Your type conversion is a mortal sin and may cost you dearly when you meet
the Great Programmer. Repent, o sinner, change thy evil ways and do
something like this:

$zere="345678";
$zee=preg_split('//',$zere,-1,PREG_SPLIT_NO_EMPTY);
if (($zee[0] % 2 != 0) && ($zee[1] % 2 == 0))
{
echo "zere=$zere\n";

}
else echo '$zee[0]=',$zee[0]," ",'$zee[1]=',$zee[1],"\n";
BTW, your assumption about C-ish equivalent between strings and arrays
does not hold water in the PHP world. Your "settype" trick would be neat,
had it worked.

--
http://www.mladen-gogala.com

[Michael Fesser]

..oO(gr****@starschiffchen.de)

>What I have is a range of integers, and I need those whose digits
alternate between odd and even. Example: 123456789. For that purpose I
have this thingy here:

settype($zee, "string");
if (($zee[0] % 2 != 0) && ($zee[1] % 2 == 0))
{
echo $zee . "<br />";

}

Just to be precise: I want to have $zee echoed, if the first digit is
odd and the second is even.

Works here on PHP 5.2. What version do you use?

>PS:
When the conditions are put like this:
if (($zee[0] & 1) && ($zee[1] & 0))
the exact same thing happens: it works with two odd conditions, but not
with one odd, one even.

In this case the second condition will always be FALSE.
It should be

if (($zee[0] & 1) && !($zee[1] & 1)) {
...
}

Micha

[Michael Fesser]

..oO(Mladen Gogala)

>Your type conversion is a mortal sin and may cost you dearly when you meet
the Great Programmer. Repent, o sinner, change thy evil ways and do
something like this:

$zere="345678";
$zee=preg_split('//',$zere,-1,PREG_SPLIT_NO_EMPTY);

Eh?

>BTW, your assumption about C-ish equivalent between strings and arrays
does not hold water in the PHP world.

Of course it does.

http://www.php.net/manual/en/languag....string.substr

>Your "settype" trick would be neat,
had it worked.

It _does_ work.

Micha

[Mladen Gogala]

On Sun, 26 Nov 2006 21:54:36 +0100, Michael Fesser wrote:

Eh?

>>BTW, your assumption about C-ish equivalent between strings and arrays
does not hold water in the PHP world.

Of course it does.

http://www.php.net/manual/en/languag....string.substr

PHP allows me to address particular characters of the string by using []
notation, but I remember having difficulties with numeric operations, when
using that.

>

>>Your "settype" trick would be neat,
had it worked.

It _does_ work.

With settype? No, it doesn't. You can't convert from an array to string
and back just like that. His code proves the opposite.
--
http://www.mladen-gogala.com

[Mladen Gogala]

On Sun, 26 Nov 2006 21:54:36 +0100, Michael Fesser wrote:

Works here on PHP 5.2. What version do you use?

No, it doesn't:
$ /tmp/ttt
PHP Notice: Array to string conversion in /tmp/ttt on line 4
$
$
$ cat /tmp/ttt
#!/usr/local/bin/php
<?php
$zee=array(3,4,5);
settype($zee, "string");
if (($zee[0] % 2 != 0) && ($zee[1] % 2 == 0))
{
echo $zee . "<br />";

}
?>

$ /usr/local/bin/php -v
PHP 5.2.0 (cli) (built: Nov 3 2006 21:13:54)
Copyright (c) 1997-2006 The PHP Group
Zend Engine v2.2.0, Copyright (c) 1998-2006 Zend Technologies
What he wants is to convert array to string for faster printing, sort like
the equivalence between char[] and *char in C language. He has an array of
integers and wants to print them as a string, provided certain numeric
conditions are met. That is why I broke a string into an array in my
snippet. In other words, he wants to be smart with "settype" function.
--
http://www.mladen-gogala.com

[Jerry Stuckle]

Michael Fesser wrote:

.oO(gr****@starschiffchen.de)

>>What I have is a range of integers, and I need those whose digits
alternate between odd and even. Example: 123456789. For that purpose I
have this thingy here:

settype($zee, "string");
if (($zee[0] % 2 != 0) && ($zee[1] % 2 == 0))
{
echo $zee . "<br />";

}

Just to be precise: I want to have $zee echoed, if the first digit is
odd and the second is even.

Works here on PHP 5.2. What version do you use?

>>PS:
When the conditions are put like this:
if (($zee[0] & 1) && ($zee[1] & 0))
the exact same thing happens: it works with two odd conditions, but not
with one odd, one even.

In this case the second condition will always be FALSE.
It should be

if (($zee[0] & 1) && !($zee[1] & 1)) {
...
}

Micha

No, it doesn't work here in PHP 5.2. It looks like it does in your case
maybe because you aren't displaying your errors?

Additionally, his test is perfectly correct. ($x % 2) will be zero for
even numbers and 1 for odd numbers.

--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
js*******@attglobal.net
==================

[Michael Fesser]

..oO(Mladen Gogala)

>On Sun, 26 Nov 2006 21:54:36 +0100, Michael Fesser wrote:

>Works here on PHP 5.2. What version do you use?

No, it doesn't:
$ /tmp/ttt
PHP Notice: Array to string conversion in /tmp/ttt on line 4
[...]

OK, obviously the OP wasn't clear enough, because my understanding of
his problem was somewhat different.

>$ cat /tmp/ttt
#!/usr/local/bin/php
<?php
$zee=array(3,4,5);

He mentioned a "range of integers", but for me this doesn't necessarily
mean an array like above. It could also be simple integers like

$zee = 123456789;

which is what I used in my test.

Micha

[Michael Fesser]

..oO(Jerry Stuckle)

>No, it doesn't work here in PHP 5.2. It looks like it does in your case
maybe because you aren't displaying your errors?

I always log errors and warnings while developing, but maybe my
understanding of the OP's problem was just different. See my reply to
Mladen.

Micha

[Mladen Gogala]

On Mon, 27 Nov 2006 17:15:13 +0100, Michael Fesser wrote:

>
OK, obviously the OP wasn't clear enough, because my understanding of
his problem was somewhat different.

I agree, the original poster didn't provide the definition for $zee, so
we can only speculate. Your guess is as good as mine.

--
http://www.mladen-gogala.com