[HELP] with Operators

[joomador]

Hi guys!

 

I am trying to understand why the final value of $m equals 40 in the following code

 

<?php
$i = 29;
$j = 11;
$m = 10;

$j = ($j - 4) / 2;
$m += $j * 10;
echo "m = ".$m."<br>"; //Equals 40
?>

 

Can anyone explain me please? I feel very confused right now. 

[jcbones]

<?php
$i = 29;
$j = 11;
$m = 10;

$j = ($j - 4) / 2; //11 - 4 = 7 divided by 2 = 3.5 ($j is now 3.5)
$m += $j * 10;  //3.5 multiply by 10 = 35 plus 10 = 45 ($m is now 45)
echo "m = ".$m."<br>";  //m = 45
?>

 

m = 45 not 40.

 

 

[btherl]

It would be 40 if the division was integer division.  But php doesn't use integer division.  From the manual:

 

There is no integer division operator in PHP. 1/2 yields the float 0.5. The value can be casted to an integer to round it downwards, or the round() function provides finer control over rounding.

[joomador]

Thanks for the quick response guys!

 

When I run the code it gives me 40 as the result.

This is the whole code

<?php
$i = 29;
$j = 11;
$m = 10;

$k = ($i++) + ($j--);
echo "k = ".$k."<br>";

$j = ($j - 4) / 2;
$m += $j * 10;
echo "m = ".$m."<br>";
?>

[harristweed]

Because j is now 10 not 11

altered here: ($k = ($i++) + ($j--)

[joomador]

Never expected to have answers so fast, you guys are great.

Thank you!

[btherl]

Oh, it's totally unrelated to integer division then   Just a coincidence.