Grouping and counting Array Values

condoug

Hi all

I am building a navigation menu which consists of a price range as such:

0 - 50
50 - 100
100 - 150
150 - 200

This menu is based on the price values of products I am searching for, so I get a list of all prices, store them in an array and get the MIN and MAX values, and then increment in blocks of 50 through the array to make my menu above. This works great.

What I need help with is doing a count of array values that exist and show a count against each menu item so my menu would be as such:

0 - 50 (23)
50 - 100 (102)
100 - 150 (76)
150 - 200 (2)

What is the best mthod to count all array values that exist between my ranges as I loop through and output my menu items?

Any help would be greatly appreciated.

Doug

dalecosp

You've got options:

If you already have an array, you want [man]count/man.

If you're looping, set a variable like $counter and increment it during the loop.

There's also a SELECT COUNT statement in most flavors of SQL.

HTH,

condoug

Thanks for the reply.

Could you provide an example in code of how I could record the count in the loop though?

i.e. as I am looping through each price range, how would you store how many values are in the array that would be associated to the price range in question.

e.g.

on the first loop the range is 0 - 50.

How would I loop through my entire array and getcount all values that are in between 0 - 50?

Many Thanks

dalecosp

Well, a general example isn't hard, I suppose:

<?php

$lowest=$second=$next=$highest=0;  // some variables to store a count in...

$prices=array(10,75,30.50,125,49.99,37.42,179,103.34); // some imaginary prices

foreach ($prices as $p) {
   if ($p<50){                    // no bounds checking ... we HOPE no price is negative
      $lowest++;
   }
   elseif ($p<100){          // "elseif" is important, otherwise ....
      $second++;              //  we might count things twice
   }
   elseif ($p<150){
      $next++;
   }
   elseif ($p<200.01){
      $highest++;
   }
   else {
      echo "Price overrun, please check data.";  // we are checking to make
   }                                                                   // sure nothing is > $200
}

// output ... of course yours is different :-)

echo "There are $lowest products under \$50, $second products under \$100,
$next products under \$150, and $highest products in the highest price
category.";

?>

bradgrafelman

You could also do something a bit more scalable, e.g.:

$ranges = array();

// length of ranges (e.g. 50 = [0..49])
$step = 50;

// sample data
$prices=array(10,75,30.50,125,49.99,37.42,179,103.34);

foreach($prices as $p) {
	$index = floor($p / $step);

if(isset($ranges[$index]))
	$ranges[$index]++;
else
	$ranges[$index] = 1;
}

// output the results
for($i = 0; $i <= max(array_keys($ranges)); $i++) {
	echo ($step * $i) . " - " . ($step * ($i + 1)) . " (" . $ranges[$i] . ")\n";
}

dalecosp

Lol, "scalable". You're so modest.

Try "scalable, elegant, future-proof, perfect." 😃

And thanks for [man]max/man. Never played with math functions much, lol.