When you work with the ZF2 Dependency Injection Container (DiC) when you make multiple requests for an instance of an object you will get the same object back each time. [...] But what if you want the injection benefits of the DiC but don't want to share the object? Use the DiC's newInstance method instead with the third parameter being false.

He includes code examples of requesting the object both ways - the usual way that returns the same object and the alternative that passes in a "false" value, complete with a debug output of each object proving they're different.

Let me start off by saying this article is about PHP and PHP alone. Other languages handle this sort of thing differently (and better). In PHP many people (and a few frameworks) return FALSE from methods when the requested value does not exist. However, I am here to tell you that if you do this, you are doing it wrong. Plain and Simple.

In his opinion, "false" is definitely not the same thing as "null" because "null" is technically the absence of a value, not a "not true" value like "false" is. He illustrates with a simple use case of a class that has methods returning various values.

A Bloom filter is a probabilistic data structure that can be used to answer a simple question, is the given element a member of a set? Now, this question can be answered via other means, such as hash table or binary search trees. But the thing about Bloom filters is that they are incredibly space-efficient when the number of potential elements in the set is large.

The filters allow false positives with a defined error rate - it gives the "yes" or "no" answer based on the content and you, the developer, decide if that answer falls within a rate that's okay for you and your app. The filters also take the same amount of time to look up items no matter how many are in the set.

He includes an example of the extension in use - defining the number of elements, the false positive allowance and adding/searching data and how the responses would come back from the checks.

In #phpc we recently had a discussion about function return values; specifically from database queries. I'm going to go on a (admittedly, rather sturdy looking) limb and say this applies to pretty much any function that returns from a data resource, not just a database .

His personal preference is to return the results data if there's matching information but to return a false value if there is an error/not results were found. He includes a snippet of example code to show the structure he's talking about. Some of the comments on the post mention things like exception handling, other similar methods other developers use and the use of nulls.

So far I've always thought false would evaluate to 0 when used in a computational context. Turns out that this isn't always the case.

His code example tries to check is a false value is greater than or equal to a negative number. The result, however (despite the thinking that false is a zero value) turns out to be false.

I randomly stumbled upon this when arguing with Mariano today if setting Model::recursive to 'false' has the same effect as setting it to '-1'. Turns out that cake uses a statement like this: if ($recursive > -1) in the core which in turn makes -1 and false do exactly the same thing.

Just a quick follow-up to my post on is_numeric vs. ctype_digit. There is one quirk with ctype_digit that may affect your choice about whether to use it.

When the string in question is empty, ctype_digit returns TRUE. However, when it is null, ctype_digit will return FALSE.

She includes code to illustrate, noting the return of each function.