How to perform conditional?

[brett]

I'd like to check these two conditions:

if ((is_page() or ($category->cat_ID === $cat)){
do something
}

but keep getting an "unexpected {..." error. If I do this, it works
fine:

if ($category->cat_ID === $cat){
do something
}

I'm guessing the array access has something to do with it. Any
suggestions?

Thanks,
Brett

[MsKitty]

Re: How to perform conditional?

Hi Brett -
You have unbalanced parentheses - one extra one on the left = try
using fewer ones so it is easier to see:
if (is_page() || $category->cat_ID === $cat) {
do something
}

Kitty

http://OpenSkyWebDesign.com

brett wrote:

I'd like to check these two conditions:
>
if ((is_page() or ($category->cat_ID === $cat)){
do something
}
>
but keep getting an "unexpected {..." error. If I do this, it works
fine:
>

[brett]

Re: How to perform conditional?

You have unbalanced parentheses

Ah! Thanks.

[Erwin Moller]

Re: How to perform conditional?

MsKitty wrote:

Hi Brett -
You have unbalanced parentheses - one extra one on the left = try
using fewer ones so it is easier to see:
if (is_page() || $category->cat_ID === $cat) {
do something
}

Correct, but advising to drop parentheses is not a good advise.
Use it everywhere, and use it right.
Dropping parentheses leads to possible confusion because tests can be
performed in a order not ment by the programmer.

I prefer this notation above all shorter ones:

if ((is_page()) || ($category->cat_ID === $cat) ) {
do something
}

That way you don't have to worry about precedence of the used terms.
eg: Is || or === evaluated first?

just my 2 cent...

Regards,
Erwin Moller

>
Kitty

http://OpenSkyWebDesign.com

>
brett wrote:

>I'd like to check these two conditions:
>>
>if ((is_page() or ($category->cat_ID === $cat)){
>do something
>}
>>
>but keep getting an "unexpected {..." error. If I do this, it works
>fine:
>>

[brett]

Re: How to perform conditional?

if ((is_page()) || ($category->cat_ID === $cat) ) {

What is the notation for equivalency? Is it "==" or "==="?

Thanks,
Brett

[Erwin Moller]

Re: How to perform conditional?

brett wrote:

>if ((is_page()) || ($category->cat_ID === $cat) ) {

>
What is the notation for equivalency? Is it "==" or "==="?

== is more loose than ===

=== also checks if the data compared is of the same type.
eg

$a = 1;
$b = "1";
if ($a == $b){
// evaluates to true
}

if ($a === $b){
// evaluates to false
}

This can be a very important extra = in some situations. :-)

A common situation where === makes sense is a functioncall that can return 0
as valid answer, eg:

// This function returns the number of elements in an array
// or it returns false if not an array is passed
function countNumber($so meArray){
if is_array($someA rray){
return count($someArra y);
} else {
return false;
}
}

Now if you use this function and feed the following 3 variables to it:
$test = array("bla",3,2 4);
$result = countNumber($te st);
if ($result){
echo "number of elements $result";
} else {
echo "Not an array!";
}

That works ok, it returns 3.

suppose $test was:
$test = 23;

Which is also ok, it would respond that $test is not an array.

Now the problem:
$test = array();

If you feed this, PHP will correctly count 0 elements, and thus return 0.

However, when used as an expression, 0 evaluates to false, thus PHP will
incorrectly say it was not an array.

If you use the following construct, this will NOT happen.

if ($result === true){
echo "number of elements $result";
} else {
echo "Not an array!";
}


Regards,
Erwin Moller

>
Thanks,
Brett