How does php evaluate the expression $x+++$x++?

Question

Please, take a look at the following expression:

$x = 20;



echo $x+++$x++; // 41

Why is the answer

41

instead of

43

?

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Answer 1

Altough I can't find any mention in the PHP docs, I guess PHP evaluates from right, and ++ acts like the same operator in C/C++ (see inc/dec PHP operator docs)

So, the expression:

$x+++$x++

in fact does (evaluated from the right):

get the value of x → 20
increment the value of x → 21
get the value of x → 21
increment the value of x → 22
sum the values got from 1 and 3 → 41

It is worth mentioning, though, that in this case the same results is obtained even if the expression is evaluated from the left.

How does php evaluate the expression $x+++$x++?

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