Ternary and Functions

[doubledee]

In this statement...

 

	$firstName = (isset($_SESSION['memberFirstName']) ? $_SESSION['memberFirstName'] : '');

 

 

Can isset() be replaced with most other functions, e.g. empty(), is_numeric(), is_null(), etc??

 

Thanks,

 

 

Debbie

 

[requinix]

Yes, in that you can put any expression in the conditional part of a ternary operator.

 

(For that particular code you'd want either isset() or !empty() but I don't think that's what you're asking about.)

[doubledee]

Yes, in that you can put any expression in the conditional part of a ternary operator.

 

Okay, great.

 

 

(For that particular code you'd want either isset() or !empty() but I don't think that's what you're asking about.)

 

Right.

 

Thanks,

 

 

Debbie

 

 

[AyKay47]

In this statement...

 

	$firstName = (isset($_SESSION['memberFirstName']) ? $_SESSION['memberFirstName'] : '');

 

 

Can isset() be replaced with most other functions, e.g. empty(), is_numeric(), is_null(), etc??

 

Thanks,

 

 

Debbie

 

the one thing I see wrong is you have the entire ternary wrapped in parenthesis, whereas you only want the condition wrapped.

This could simply have been a typo, however wanted to point it out.

[doubledee]

In this statement...

 

	$firstName = (isset($_SESSION['memberFirstName']) ? $_SESSION['memberFirstName'] : '');

 

 

Can isset() be replaced with most other functions, e.g. empty(), is_numeric(), is_null(), etc??

 

Thanks,

 

 

Debbie

 

the one thing I see wrong is you have the entire ternary wrapped in parenthesis, whereas you only want the condition wrapped.

This could simply have been a typo, however wanted to point it out.

 

I don't follow you.

 

Can you repost how it should look?

 

Thanks,

 

 

Debbie

 

[AyKay47]

$firstName = (isset($_SESSION['memberFirstName'])) ? $_SESSION['memberFirstName'] : '';

[doubledee]

$firstName = (isset($_SESSION['memberFirstName'])) ? $_SESSION['memberFirstName'] : '';

 

It looks like any of these would work...

 

$memberID = isset($_SESSION['memberID']) ? $_SESSION['memberID'] : '';

$memberID = (isset($_SESSION['memberID'])) ? $_SESSION['memberID'] : '';

$memberID = (isset($_SESSION['memberID']) ? $_SESSION['memberID'] : '');

$memberID = ((isset($_SESSION['memberID'])) ? $_SESSION['memberID'] : '');

 

Does one versus the other really matter?

 

 

Debbie

 

 

[requinix]

1/2 and 3/4 are identical pairs. The parentheses around the condition mean nothing, but parentheses around the whole ternary could make a difference depending on operator precedence.

$variable = $condition ? $a : $b;
// equivalent to $variable = ($condition ? $a : $b) because ?: has higher precedence than =

$variable == $condition ? $a : $b;
// equivalent to ($variable == $condition) ? $a : $b because == has higher precedence than ?:

Operator precedence table

[doubledee]

1/2 and 3/4 are identical pairs. The parentheses around the condition mean nothing, but parentheses around the whole ternary could make a difference depending on operator precedence.

$variable = $condition ? $a : $b;
// equivalent to $variable = ($condition ? $a : $b) because ?: has higher precedence than =

$variable == $condition ? $a : $b;
// equivalent to ($variable == $condition) ? $a : $b because == has higher precedence than ?:

Operator precedence table

 

So which format would you recommend?

 

 

Debbie

 

[requinix]

I personally like having parentheses around the whole thing because of how it looks (literally) to me.

$firstName = (isset($_SESSION['memberFirstName']) ? $_SESSION['memberFirstName'] : '');

If you're not sure about the precedence thing then I recommend using the parentheses too, but ultimately it's up to your preferences and style.