Add Yoda Conditions style

[mrDlef]

Yoda Conditions

When doing logical comparisons involving variables, always put the variable on the right side and put constants, literals, or function calls on the left side. If neither side is a variable, the order is not important. (In computer science terms, in comparisons always try to put l-values on the right and r-values on the left.)

if (true == $theForce) {
    $victorious = youWill($be);
}

In the above example, if you omit an equals sign (admit it, it happens even to the most seasoned of us), you’ll get a parse error, because you can’t assign to a constant like true. If the statement were the other way around ($theTorce = true), the assignment would be perfectly valid, returning 1, causing the if statement to evaluate to true, and you could be chasing that bug for a while.

A little bizarre, it is, to read. Get used to it, you will.

This applies to ==, !=, ===, and !==. Yoda conditions for <, >, <= or >= are significantly more difficult to read and are best avoided.

[geoffroy-aubry]

• Why do you say that this apply to === and !== ?
• From my point of view the lack of readability outweighs the benefits described above

[geoffroy-aubry]

Do not use Yoda:

• The Programatic Programmer: From Journeyman to Master
• Clean Code: A Handbook of Agile Software Craftsmanship
• Design Patterns: Elements of Reusable Object-Oriented Software
• Code Complete: A Practical Handbook of Software Construction, Second Edition

[geoffroy-aubry]

Do not use Yoda:

• jQuery
• Zend
• Laravel
• React
• Underscore
• AngularJS
• Backbone.js
• React
• Closure
• Ruby on Rails (RoR)
• CakePHP

[geoffroy-aubry]

The Clean Coder: « I dislike any statement in code that causes the reader to do a double-take. Code that protects the author at the expense of the reader is flawed code. »

[geoffroy-aubry]

Even if I vote against, I thank you for your proposal :)

[nunomaduro]

Great proposal! This thumbs vote format is really cool. For this proposal I vote against tho.

[wodzy]

I think this makes the code harder to read. I vote against too.

[mrDlef]

Here are some good resources about that:

• Yoda Conditions: To Yoda or Not to Yoda
• Why using Yoda conditions you should probably not be

As we don't have enough unit tests and linters for our legacy code I thought it would be a good way to be sure of the behavior of a condition. Cool to discuss on that anyway.