Can someone please explain to me why the following javascript code produces an alert with 321 and the PHP code produces 1.
I know the PHP code evaluates the expression and returns true or false. What I don't know is why in JavaScript it works like a ternary operator. Is it just the way things were implemented in the language?
var something = false; var somethingelse = (something || 321); alert(somethingelse); // alerts 321
$var = '123'; $other = ($var || 321); echo $other; // prints 1
Thanks!
Is it just the way things were implemented in the language?
Yes, JavaScript does it a bit differently. The expression (something || 321) means if something is of a falsy value, a default value of 321 is used instead.
In conditional expressions || acts as a logical OR as usual, but in reality it performs the same coalescing operation. You can test this with the following:
if ((0 || 123) === true)
alert('0 || 123 evaluates to a Boolean');
else
alert('0 || 123 does not evaluate to a Boolean');
In PHP the || operator performs a logical OR and gives a Boolean result, nothing else.
I'm actually surprised javascript did not alert 1 or true as well. The syntax you want for js is:
var somethingelse = something || 321;
Wrapping parentheses around something evaluates it as truthy / falsey. For php your are saying:
//$other will equal true if $var is true or 321 is true.
$other = ($var || 321);
A matching statement in php would look like:
$other = ($var) ? $var : 321;
Just to add on boltClock answer since I can't comment - If you want it be a Boolean value you can parse it to bool like this:
var somthing = !!(somthingelse || 321);
In PHP ($var || 321); is evaluated and assigned to $other.
You can use this in PHP.
($other = $var) || $other = 321;
Update: As BoltClock said in Javascript var somethingelse = (something || 321) seeks to assign a default value to the variable if something is false.
