Att Trejder and inverse boolean tests

[jacmoe (Jacob Moena)]

In this comment:

http://www.yiiframew…n/config/#c2262

Trejder writes:

This extension’s author has some kind of interesting approach or coding technique! For example, look at this particular piece of code:

private function _getConfig($db, $cache)

{

    if (true === $this->autoCreateConfigTable)

    {

        $this->_createConfigTable($db);

    }

 

    if (false === $cache || false === ($this->_config = $cache->get(self::CACHE_KEY)))

    {

 

        $dbReader = $db->createCommand("SELECT * FROM '{$this->configTableName}`")->query();

 

        while (false !== ($row = $dbReader->read()))

        {

            $this->_config[$row['key']] = $row['value'];

        }

 

        if (false !== $cache)

        {

            $cache->set(self::CACHE_KEY, $this->_config);

        }

    }

}

I wanted to comment on the comment, but I thought I’d just post it here.

That’s a very good coding practice!

I tend to forget it constantly - mainly due to the fact that it just feels very unnatural - but it’s awesome because it is not possible to accidentally assign something.

This would pass but accidentally change the variable:

if($cache = false)

This wouldn’t:

if(false = $cache)

So, it’s a good practice. IMO.

It’s easier to shoot yourself if you don’t use this inverse test technique, if you use non-strict comparison operators, like ‘==’.

Late at night, it’s hard to spot the difference between ‘==’ and ‘=’ …

The technique above is a better-safe-than-sorry approach.

[jacmoe (Jacob Moena)]

Forgot to mention the rationale:

Put the constant on the right hand side.

Since you can’t assign to a constant, it will fail if you accidentally write ‘=’ instead of ‘==’.

[andy_s (Arekandrei)]

It’s awful to write

if ($var == true) { ... }

instead of

if ($var) { ... }

IMHO of course…

[jacmoe (Jacob Moena)]

That really depends on how $var is initialized and what type it is.

I tend to use the if($var) form myself - but sometimes it bites you in the rear.

And if you are comparing it as a boolean, empty/non-empty or other type/constant.

IMO.

[mdomba (Maurizio Domba Cerin)]

I’m mainly using this style… it comes handy with other data comparison… not too much with boolean…

but for example

if(null==$var)

or

if(10==$var)

or

if(User::STATUS_ADMIN==$user)

[trejder (Tomasz)]

You could at least PM my, jacmoe, that you are opening discussion upon my comment! You are a bad boy!

Date and time columns from the database in the model

Late at night, it’s hard to spot the difference between ‘==’ and ‘=’ …

The technique above is a better-safe-than-sorry approach.

No, it’s not! All you need is a good software for editing your PHP files. For example using NetBeans (wonderful, but a bit slow!) you will always get green underline in such situations. In this particular, with comment saying “Possible accidental assignment. Assignments in conditions should be avoided”. Brilliant!

[tonydspaniard (Antonio)]

No, it’s not! All you need is a good software for editing your PHP files. For example using NetBeans (wonderful, but a bit slow!) you will always get green underline in such situations. In this particular, with comment saying “Possible accidental assignment. Assignments in conditions should be avoided”. Brilliant!

Also ZendStudio…

[trejder (Tomasz)]

Also ZendStudio…

With the little difference, that Zend Studio isn’t free, am I right? :]

[tonydspaniard (Antonio)]

With the little difference, that Zend Studio isn’t free, am I right? :]

right