generating resources for each level of building - php

Question

Is it possible to change this code into function without using a loop?
$start = 80;
for ($i = 1; $i <= 10; $i++) {
$start = $start * 1.5;
echo "level ".$i.": ".$start."<br>";
}
function generate($start, $level){
// some code
return $start;
}

Answer 1

For level 1 you have:
$start = $start * 1.5;
For level 2 $start is result from level 1, so:
$start = ($start * 1.5) * 1.5;
This same as
$start = $start * 1.5 * 1.5;
And can be simplified to
$start = $start * pow(1.5, $level);
In the end your function should look like:
function generate($start, $level){
return $start * pow(1.5, $level);
}

Answer 2

if you want to get the same result(include the level print to screen) you can use this code:
function generate2($start, $from,$to){
if($from==$to+1)
return 1.5;
$tmp=$start*1.5;
echo "level ". ($from).": ".$tmp."<br>";
return 1.5*generate2($tmp,$from+1,$to);
}
Or this:
<?php
define ("MAX_LEVEL",10) ;
function generate($start, $level)
{
if($limit==0)
return 1.5;
$tmp=$start*1.5;
echo "level ". (MAX_LEVEL-$level+1).": ".$tmp."<br>";
return 1.5*generate($tmp,$level-1);
}
Here some check code:
$start = 80;//<=================your code
for ($i = 1; $i <= 10; $i++) {
$start = $start * 1.5;
echo "level ".$i.": ".$start."<br>";
}
echo"---------------------------- <br>";
generate(80,10);//<====================my code
echo"---------------------------- <br>";
generate2(80,1,10);
?>
if you not need the prints you can use very simple function:
function generate($start, $level){
return $start * pow(1.5, $level);
}

Answer 3

Here you go, a solution without "visible" loop:
generate(80,10);
function generate($start, $level){
$i=1; // Just a var
$array = array_fill(0, $level, $start); // create an array with $level elements, with value $start
array_map(function($v)use(&$i){ // Loop through the array and use $i
echo "Level $i: ".(array_product(array($v, pow(1.5, $i++))))."<br>"; // Some basic math and output
}, $array);
}
Online demo
Note that you'll need PHP 5.3+ since this function is using an anonymous function

Answer 4

Or, if you need just to output $start:
function generate($start, $limit)
{
$start = $start * 1.5;
echo $start."<br>";
if($limit>1)
return(generate($start,$limit-1));
}
generate(80,10);
My question - how to properly echo $level, without third parameter (0, in this case which should be incremented, no decremented:))? :)
EDIT: I would like to know better solution which will do the same, with two args:
function generate2($start, $limit,$base)
{
$start = $start * 1.5;
echo "level ".$base.": ".$start."<br>";
if($base<$limit)
return(generate2($start,$limit,$base+1));
}
generate2(80,10,1);
And final edit:
function generate($start, $limit,$i=0)
{
$i++;
$start = $start * 1.5;
echo "level ".$i.": ".$start."<br>";
if($limit>1)
{
return(generate($start,$limit-1,$i));
}
}
generate(80,10);
as answer to my self. :) Please test it (before down votes:)), and let me know about issues... Oh, i see - OP wants just 1 result, LOL...
Question wasn't clear to me (and not just to me, it seems) :)