PHP Shorthand If/Else Using Ternary Operators (?:)
An essential part of programming is evaluating conditions using if/else and switch/case statements. If / Else statements are easy to code and global to all languages. If / Else statements are great but they can be too long.
Ternary operator logic is the process of using "(condition) ? (true return value) : (false return value)" statements to shorten your if/else structures.
What Does Ternary Logic Look Like?
/* most basic usage */ $var = 5; $var_is_greater_than_two = ($var > 2 ? true : false); // returns true
What Are The Advantages of Ternary Logic?
There are some valuable advantages to using this type of logic:
- Makes coding simple if/else logic quicker
- You can do your if/else logic inline with output instead of breaking your output building for if/else statements
- Makes code shorter
- Makes maintaining code quicker, easier
- Job security?
Tips for Using Ternary Operators
Here are a few tips for when using "?:" logic:
- Don't go more levels deep than what you feel comfortable with maintaining.
- If you work in a team setting, make sure the other programmers understand the code.
- PHP.net recommends avoiding stacking ternary operators. "Is [sic] is recommended that you avoid "stacking" ternary expressions. PHP's behaviour when using more than one ternary operator within a single statement is non-obvious."
- If you aren't experienced with using ternary operators, write your code using if/else first, then translate the code into ?'s and :'s.
- Use enough parenthesis to keep your code organized, but not so many that you create "code soup."
More Sample Usage
Here are a couple more uses of ternary operators, ranging from simple to advanced:
/* another basic usage */ $message = 'Hello '.($user->is_logged_in() ? $user->get('first_name') : 'Guest');
/* shorthand usage */ $message = 'Hello '.($user->get('first_name') ?: 'Guest');
/* echo, inline */ echo 'Based on your score, you are a ',($score > 10 ? 'genius' : 'nobody'); //harsh!
/* a bit tougher */ $score = 10; $age = 20; echo 'Taking into account your age and score, you are: ',($age > 10 ? ($score < 80 ? 'behind' : 'above average') : ($score < 50 ? 'behind' : 'above average')); // returns 'You are behind'
/* "thankfully-you-don't-need-to-maintain-this" level */ $days = ($month == 2 ? ($year % 4 ? 28 : ($year % 100 ? 29 : ($year %400 ? 28 : 29))) : (($month - 1) % 7 % 2 ? 30 : 31)); //returns days in the given month
To learn more about ternary operators and usage, visit PHP.net Comparison Operators.