How come this code below echo's 2 and does not give an error, does it just ignore +1+2+3+4 ?
I've searched but couldn't find an answer.
<?php
$i = 1;
$i+++1+2+3+4;
echo $i;
That line:
$i+++1+2+3+4;
Says:
$i$i pre increment to +1+2+3+4, but don't store the result anywhere.Hence $i == 2.
If you wouldn't want it to be ignored, you should store the result:
$i = $i+++1+2+3+4;
All is fine. You just forgot the assignment, so i is affected only by ++ operator:
<?php
$i = 1;
$x = $i+++1+2+3+4;
echo "{$i} vs "{$x}";
would return
2 vs 11
You never assign the completed operation anywhere:
These two are functionally equivalent:
$i++;
$i = $i + 1;
both will increment $i by 1, and save that incremented value in $i
With $i+++1+2+3+4 you're essentially executing
($i++) + 1 + 2 + 3 + 4
which is
$i = $i + 1;
1 + 2 + 3 + 4; // useless, result not stored anywhere
so which increments $i by 1, saves that to $i, then does the other additions. But since those aren't being saved anywhere, the result is thrown away.
if you had
php > $i = 1;
php > $i = $i+++1+2+3+4;
^^^^^----add this
php > echo $i;
11
then it would have worked as you expect.
$i++ means add 1 to $i.
and like python, the +1+2+3+4 means add the value of $i pre increment to +1+2+3+4 but don't store it anywhere.(so no memory address or anything like that...).
so what you get is just $i==2