PHP equation from JavaScript - php

Question

I have this JavaScript equation which I'm now trying to transform to PHP.
JavaScript:
LVL=new Array();
LVL[1]=128;
LVL[0]=128;
m=.05;
for (i=1;i<101;i++) {
if (i>1) {
LVL[i]=Math.floor(LVL[i-1]+(LVL[i-1]*m));
m=m+.0015;
}
}
then it's a bunch of document.writes of a table and a for loop.
Here's what I have so far (which is NOT working):
<?php
$n = 1; // level
$m = .05; // exp modifier
$exp = floor($n*1+($n-1)*$m);
echo "Level " . $n . ", exp needed: " . $exp; // 128 exp
?>
The PHP output is: Level 1, exp needed: 1 and that's WRONG.
It SHOULD say: Level 1, exp needed: 128
What am I doing wrong?

Answer 1

A direct transcription:
$LVL = array();
$LVL[1] = 128;
$LVL[0] = 128;
$m = .05;
for ($i = 1; $i < 101; $i++)
{
if ($i > 1)
{
$LVL[$i] = floor($LVL[$i-1] + $LVL[$i-1]*$m);
$m = $m + .0015
}
}
You need to build the array as its built bottom-up

Answer 2

You do a couple of errors:
you use the index (the level) as it is the amount of the experience points needed to
reach the level.
you forgot the for (if you are testing the formula it is ok)
the code so far:
$lvl = array(128,128);
$modifier=.05;
for ($i=1;$i<101;i++) {
$lvl[$i]=floor($lvl[$i-1]*(1+$modifier));
$modifier+=0.0015;
}
foreach ($lvl as $level=>$points) {
echo "Level " . $level . ", exp needed: " . $points ."\n<br />"; // 128 exp
}