I have never encountered this in javascript thus far although I am aware : ? means else if. I am having trouble figuring out how to lay it out in PHP. Here is what I did - where am I going wrong if it is wrong?
JSCRIPT
var midparams = dparams2.isramped() ? dparams2 : DailyParams.avg(dparams1, dparams2);
PHP
$midparams = $dparams2->isramped() if $dparams2 = $midparams else $DailyParams->avg($dparams1, $dparams2);
You can do this:
$midparams = $dparams2->isramped() ? $dparams2 : $DailyParams->avg($dparams1, $dparams2);
Or this:
if($dparams2->isramped()) {
$midparams = $dparams2;
} else {
$midparams = $DailyParams->avg($dparams1, $dparams2);
}
You can read more about the ternary operator in:
You've got 2 options. 1st one is almost the same as JavaScript
$midparams = ($dparams2 -> isramped()) ? $dparams2 : $DailyParams->avg($dparams1, $dparams2);
The second one is more trivial:
if ($dparams2 -> isramped()) {
$midparams = $dparams2;
} else {
$midparams = $DailyParams->avg($dparams1, $dparams2);
}
First one says: midparams will be dparams if statement before is true, or $DailyParams->avg($dparams1, $dparams2) if it is not. Second is the same thing but in a more straight forward fashion.
This is called the ternary operator. It sets a variable based on a condition. In PHP, what it's saying (in pseudocode here) is:
setSomeVariable = (test condition) ? value if true : value if false;
So, if for example, you wanted to set the value of $a to 10 if the $score is greater than 100, or set $a to 0 if $score is less than or equal to 100, the code would look like this:
$a = ($score > 100) ? 10 : 0;
See the documentation here: http://php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary
It's called a ternary operator; it's used the same way in PHP as it is in JavaScript -
/* most basic usage */
$var = 5;
$var_is_greater_than_two = ($var > 2 ? true : false); // returns true
Straight from David Walsh's blog - http://davidwalsh.name/php-shorthand-if-else-ternary-operators
Also note: I think you're thinking about it a bit backwards -
It is not (repeat, not) used like this:
$var = (assign this value) ? (if this is true) : (otherwise, assign this value)
It is used like this:
$var = (is this true) ? (then assign this value) : (otherwise, assign this value)
EDIT Per @Pointy pointy-ing this out, there is a slight difference between how the statements are evaluated in JavaScript in PHP - See example #4 in the documentation. Although only a crazy person would write a long-winded unparenthesized ternary expression. http://php.net/manual/en/language.operators.comparison.php#language.operators.comparison.ternary
? : operations, while JavaScript (and pretty much every other language that has the construct) is left-biased.
ifandelsein the middle of an expression like that?