PHP 5.5 First Look
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Dereferencing strings and arrays


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PHP 5.5 First Look

with Jon Peck

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Video: Dereferencing strings and arrays

One of the pieces of functionality that's been available in many different languages, but was missing from PHP, was the ability to dereference strings and array literals. Dereferencing means the ability to get the address of an item that's stored elsewhere. Dereferencing strings is a great way to obfuscate code. Meaning it makes it hard to read. So be careful when choosing whether or not to use it. I'm going to use array dereferencing to get a random element of a one off array without using a variable. I'm going to navigate to classes, Log.php and then open the generate method.
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Watch the Online Video Course PHP 5.5 First Look
42m 29s Intermediate Jun 14, 2013

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Join author Jon Peck as he demonstrates new functionality in PHP 5.5, including generators, the try-catch-finally execution model, and a brand-new password hashing API. A number of existing behaviors, such as the foreach() and empty() functions, have also been updated, and Jon explores what changed and how it can be used. Throughout this course, you'll learn to add new functionality to a simple deck of cards class using these new and updated features, and how to use them for the basis of your own project.

Topics include:
  • Using generators to create simple iterators
  • Dereferencing strings and arrays
  • Enhancing security with the password hashing API
  • Replacing APC with OPcache
  • Normalizing Boolean and unpack() behavior
  • Surveying the removed, incompatible, and deprecated functionality
Subject:
Developer
Software:
PHP
Author:
Jon Peck

Dereferencing strings and arrays

One of the pieces of functionality that's been available in many different languages, but was missing from PHP, was the ability to dereference strings and array literals. Dereferencing means the ability to get the address of an item that's stored elsewhere. Dereferencing strings is a great way to obfuscate code. Meaning it makes it hard to read. So be careful when choosing whether or not to use it. I'm going to use array dereferencing to get a random element of a one off array without using a variable. I'm going to navigate to classes, Log.php and then open the generate method.

I use this to generate fake log entries. Currently action is blank. There are three possible actions. Actions equals array, filled with draw, pass, and fold. I'm going to do this the old fashioned way first. I'm going to create a new variable, random action, and assign it to a random element from the actions array. Random action equals actions array rand actions, including setting the key this is three lines of code and generated two unnecessary variables.

I could save a line and just assign action to a random element but there's still leftover. Now with PHP 5.5 I can do this in one line. I'm going to delete actions and random action and I'm going to create a one off array then dereference it using brackets and a key that I wish to access, which is a random number between zero and two. So, actions equals array, draw, pass, fold. I'm going to dereference accessing a random index key using rand, zero, two.

If I wanted to strings can be de-referenced in the same way, but for this application there really isn't much need. Something like echo hello 1, and this would just return e. Remove the echo and save the file. This feature probably isn't going to see a lot of use, but it makes php more consistent. Regardless, now that I have a way of generating log entries, I going to write them to the database very quickly, and that can be kind of a sensitive operation.

Find answers to the most frequently asked questions about PHP 5.5 First Look .


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Q: How do I import the php55.sql file into MySQL?
A: Copy the php55.sql file from the Exercise Files folder to somewhere you can access it at the command line. (In this course, that's the 'sandbox' folder.)
 
Then type:
mysql -user=sandbox -password=sandbox sandbox < php55.sql
 
Be sure to substitute your MySQL username and password if necessary.
 
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