usort

Anon

Hello Everyone,

I have an array, and in that array is points:
$playerArray[0][9]= 3;
$playerArray[1][9]=5;
$playerArray[2][9]= 11;
$playerArray[3][9]=2;
$playerArray[4][9]= 15;

I am trying to sort so that the the player with the most points is displayed first. I used usort for this. My problem is that it displays by least points first to most points. And my next problem is that it it will order the example above as:

11, 15, 2, 3, 5

rather than
2, 3, 5, 11, 15

It looks as though it is only comparing the first place in then number. So instead of comparing 15 it compares 1.

This is my code:
usort($playerArray, "cmp");

function cmp ($a, $b) {

    return strcmp($a["9"], $b["9"]);

}

Thank you for your time. Any help is greatly appreciated!

[deleted]

usort sorts the array according to what the 'cmp' function returns.

In your case, you are checking wether $a["9"] is the same as $b["9"].

This is not really correct, because it will return zero if they are not equal, and one if they are.

but, what you should be returning is -1 if one is less than the other, or zero if both are the same, or 1 if one is more than the other.

Read the manual page again, then look at the function below:
http://www.php.net/manual/en/function.usort.php

$playerArray[0][9]= 3; 
$playerArray[1][9]=5; 
$playerArray[2][9]= 11; 
$playerArray[3][9]=2; 
$playerArray[4][9]= 15; 

echo '<pre>';
usort($playerArray, "cmp"); 
print_r($playerArray);

function cmp ($a, $b)
{ 
  // Check if they are equal
  if ($a[9] == $b[9])
  {
    // Yes they are equal, return zero
    return 0;
  }
  else
  {
    // They are not equal, is A larger than B?
    if ($a[9] > $b[9])
    {
      // A is larger than B, return 1
      return 1;
    }
    else
    {
      // A is not larger than B, and it is not equal, so A must be less than B, return -1
      return -1;
    };
  };
} 