what is the different between this in php?

Question

what is the difference between

$totalprice += $product['price'] * $product['count'];

and

$totalprice = $product['price'] * $product['count'];

both give the same result. so what's the use of (+=) ?

score 3 · Accepted Answer · answered Sep 01 '10 at 19:42

3

+= is a shorthand for adding the result to the target. The first one is equivalent to:

$totalprice = $totalprice + ($product['price'] * $product['count']);

There are also other compound operators -=, *=, /=, etc.

answered Sep 01 '10 at 19:42

efritz

5,125
4
24
33

1

@sagarmatha you're getting the same result because `$totalprice` is presumably currently 0, but you're doing the extra processing. If you have globals auto-register, or set this value somewhere else, that value could change. – Rudu Sep 01 '10 at 19:44

score 1 · Answer 2 · answered Sep 01 '10 at 19:43

1

They only give the same result if $totalprice starts off at 0 or uninitialised

The += syntax is shorthand for the following:

$myvar += a;

is equivalent to

$myvar = $myvar + a;

answered Sep 01 '10 at 19:43

Martijn

11,964
12
50
96

score 0 · Answer 3 · answered Sep 01 '10 at 19:43

0

The += takes $totalprice and adds $product['price'] * $product['count'] to it. The = asigns the value of $product['price'] * $product['count'] to $totalprice.

If you are getting the same result, its because $totalprice started off equal to 0.

answered Sep 01 '10 at 19:43

GrandmasterB

3,396
1
23
22

score 0 · Answer 4 · answered Sep 01 '10 at 19:43

0

If $totalprice is zero to start, then they're the same. Otherwise, they're different.

As others have pointed out, $i += $j is shorthand for $i = $i + $j.

answered Sep 01 '10 at 19:43

John

15,990
10
70
110

what is the different between this in php?

4 Answers4