Sorting Arrays and data that isn't in a database.

[Mateobus]

Ok My Setup is as follows: there are two arrays, one with a name value, the other one with a number of points.  I want to make a top ten list of the points.
so it looks like this.

$name[1] = "John";
$name[2] = "Peter";
$name[3]="Jeff";

$points[1] = 7;
$points[2]= 8;
$points[3]= 2;

I want to print the following list

1.Peter -8
2. John -7
3. Jeff -2

I can change the arrays to something more logical if necesary.

[bltesar]

try
[code]
arsort($points);  //sorts array by values highest to lowest, preserving key=>value relationship.

foreach($points as $key=>$value)
{
    echo $name[$key].'-'.$value.'<br>';
}
[/code]

of course, you could achieve your objective in many differnet ways.

[HeyRay2]

To limit how many items are printed out, add this to the code from [b]bltesar[/b]:

[code=php:0]
arsort($points);  //sorts array by values highest to lowest, preserving key=>value relationship.

// How many results to show
$limit = 10;

for($i = 1; $i <= $limit, $i++){
  foreach($points as $key=>$value)
  {
    echo $i.". ".$name[$key].'-'.$value.'<br>';
  }
}
[/code]

[king arthur]

You need to put this data into the same array, otherwise when you sort the array with the points in it you will lose the association with the names.

E.g. $name_and_points = array(array("name"=>"John", "points"=>7),
                                         array("name"=>"Peter", "points"=>8 ),
                                         array("name"=>"Jeff", "points"=>2));

Then do a usort on the points column.

[bltesar]

doesn't arsort preserve the key=>value relationships, and so the assocaition between names and points should be preserved?

another approach is to set up your array as follows:
[code]
$data=array('John'=>7, 'Peter'=>8, 'Jeff'=>2);
arsort($data);
[/code]

[king arthur]

[quote author=bltesar link=topic=103746.msg413418#msg413418 date=1155237717]
doesn't arsort preserve the key=>value relationships, and so the assocaition between names and points should be preserved?
[/quote]

How can it if they are in two separate arrays?

[Ninjakreborn]

[quote]bool arsort ( array &array [, int sort_flags] )[/quote]
From the manual it seems it can take 2 arrays

[Barand]

[quote author=bltesar link=topic=103746.msg413418#msg413418 date=1155237717]
doesn't arsort preserve the key=>value relationships, and so the assocaition between names and points should be preserved?[/quote]

Yes, it works fine. But I would go with your alternative offering below which keeps the names and values together in an easy-to-sort 1 dimensional array

[quote]
another approach is to set up your array as follows:
[code]
$data=array('John'=>7, 'Peter'=>8, 'Jeff'=>2);
arsort($data);
[/code]

[/quote]

[Barand]

[quote author=businessman332211 link=topic=103746.msg413429#msg413429 date=1155238167]
[quote]bool arsort ( array &array [, int sort_flags] )[/quote]
From the manual it seems it can take 2 arrays
[/quote]

No.

"array &array" means the first argument is the array you want to sort, passed by reference.

[bltesar]

yes, it will still work with two arrays, but you only need to pass the $points array to the arsort function. 

both arrays share the same key, so you sort $points by its values(not keys) and then go through $points and use the keys to reference back to the $names array.