How to write multiple variable if statement in php

Question

So I have an if-statement and I am not sure how is the best way to write it. Or if there is a proper way of writing it. Can I just use && every time or should I separate them with more () or does it really matter, is there a difference in performance ect?

$a = 10;
$b = 20;
$c = 8;
$d = 25;
$e = "";
$f = "not blank";

// FIRST EXAMPLE
if (!empty($e) && !empty($f) && $a <= $c && $b <= $d)
{
    // do something here
}

OR

if ( (!empty($e) && !empty($f)) && ($a <= $c && $b <= $d))
{
    // do something here
}

If all your conditions are AND, then there's no need for brackets at all. If you have some OR conditions combined with AND conditions, you'll likely need some brackets. — Qirel
– Qirel, Commented Dec 4, 2016 at 16:24

Ben Plummer · Accepted Answer · 2016-12-04 16:31:20Z

Generally whether you need to use brackets depends on the precedence of the operators you are using in the condition of the if statement. See the official PHP documentation on it for more detail.

Personally, in the case of if statements (and code in general within reason) I favour readability above all.

For instance, with the following if statement you suggested:

if (!empty($e) && !empty($f) && $a <= $c && $b <= $d)
{
    // do something here
}

For someone who is not familiar with the code, it can initially take a bit longer to see what's happening. There are many ways to combat this. One example is splitting the condition into separate if statements and maybe throwing exceptions if it fits in with your logic. In this case your example could become something like this:

if (empty($e) || empty($f))
{
    // throw exception as one or both of $e or $f is empty
}

if ($a <= $c && $b <= $d)
{
    // do something here
}

The example may not be logically correct but hopefully it helps in throwing a different perspective on things.

mitch · Accepted Answer · 2016-12-04 16:23:49Z

0

It only depends of your needs. Don't use brackets when you don't need it. It making code harder to read. In your case you shouldn't use brackets, just:

if ( !empty($e) && !empty($f) && $a <= $c && $b <= $d)
{
    // do something here
}

In this case there is completely no need to use more brackets because you have only &&. As it comes to performance, less brackets - less work for interpreter.

edited Dec 4, 2016 at 16:23

answered Dec 4, 2016 at 16:18

mitch

2,2454 gold badges28 silver badges46 bronze badges

2 Comments

Jayce Over a year ago

So as Qirel pointed out above only use extra brackets for && while using || with it?

mitch Over a year ago

Yes, if you are using || in most cases you will need brackets. Just like in maths (2+2)*2 - brackets are executing first.

Ali · Accepted Answer · 2016-12-04 16:21:56Z

0

You need to keep each statement in different brackets

if ( (!empty($e) && (!empty($f) && ($a <= $c) && ($b <= $d))
{
 // do something here
}

edited Dec 4, 2016 at 16:21

answered Dec 4, 2016 at 16:18

Ali

739 bronze badges

Collectives™ on Stack Overflow

How to write multiple variable if statement in php

3 Answers 3

Comments

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related