Using usort for custom sorting php array

Question

So I have array with Passive, Q, Q2, W, W2, E, E2, R, R2 and I'd like to be in the order I wrote it in.

$SpellTitle = array("Passive", "W", "Q", "Q2", "W2", "R", "E", "E2", "R2");

I've read about using usort(), but I don't really understand how to use it.

UPDATE!

$SpellTitle is a dynamic array loaded from database so length will differ and it will be randomly set in that array.

Answer 1

usort takes a user defined function as a second parameter. That function has to return an integer value of less than zero, zero, or greater than zero. This function has to take two parameters - array values to be compared to each other. If the first value is "lower" than the second, function returns a value less than zero, otherwise greater then zero. If values are equal, function must return zero.

So, If You want to make a custom function that sotrs integer or float values, You could use:

function cmp($a, $b) {
    if((float) $a == (float) $b) {
        return 0;
    } else {
        return ((float) $a < (float) $b) ? -1 : 1;
    }
}

Answer 2

Use PHP asort

asort - Sort an array and maintain index association.

Example:

$SpellTitle = array("Passive", "W", "Q", "Q2", "W2", "R", "E", "E2", "R2");
asort($SpellTitle);
print_r($SpellTitle);

output:

Array
(
  [6] => E
  [7] => E2
  [0] => Passive
  [2] => Q
  [3] => Q2
  [5] => R
  [8] => R2
  [1] => W
  [4] => W2
)

Note that array indices order was maintained too.
Hope this help.