$a++

Question

What happens if
$a =2 $b=$a++
Echo $b;
The answer is 2 ,how does not the value of a increases .Then why the value of "a" does not increase coz "++" shows increasing and when happened if vice versa ,for example
$a=2 $b=$++a
Echo $a; what is the output of both

Answer 1

++a is pre-increment and a++ is post-increment.

So:

b=++a, first increment a then assign to b, so b=3

b=a++, b=a=2 then increment a to 3