get index of array with condition - php

Question

I have this kind of array :
$arrVar = array(
0 => array(
'val'=> 9
),
1 => array(
'val'=> 12,
),
2 => array(
'val'=> 4
),
);
How do I make a function that returns the index of an array based on a variable $myVar?
For example :
if $myVar = 4 the function will return $arrVar['2']
if $myVar = 8 the function will return $arrVar['2']
if $myVar = 10 the function will return $arrVar['0']
This is my array
$arrVar = array(
0 => array(
'qty'=>9,
'disc'=> 0.15
),
1 => array(
'qty'=>12,
'disc'=> 0.20
),
2 => array(
'qty'=>4,
'disc'=> 0.10
),
);
when customer A buy 4 products he will get disc 10%
or when customer A buy 8 products he will get disc 10%
or when customer A buy 10 products he will get disc 15%

Answer 1

Use following php function to calculate your discount percentage:
function searchArr($needle) {
global $arrVar;
$arr=array();
foreach($arrVar as $key => $value) {
$vals = array_values($value);
$arr[$vals[0]] = $vals[1];
}
ksort($arr);
$prev=0;
foreach($arr as $key => $value) {
if ($needle < $key)
return 100 * ($prev==0 ? $value : $prev);
$prev = $value;
}
return 100 * $prev;
}
TESTING:
echo "Discount: " . searchArr(4) . "%\n";
echo "Discount: " . searchArr(8) . "%\n";
echo "Discount: " . searchArr(10) . "%\n";
echo "Discount: " . searchArr(12) . "%\n";
OUTPUT:
Discount: 10%
Discount: 10%
Discount: 15%
Discount: 20%
See this code running here: http://ideone.com/zLDen