Question

This is my problem:
I need to get four members of an array that have the maximum values of an attribute. I have seen the max() function already, but that one only gets me one member, and I need four. For example, I can have an array like this:

array( 
    array(
        "1", 
        "10"
    ), 
    array(
        "9", 
        "10"
    ), 
    array(
        "3", 
        "10"
    ), 
    array(
        "4", 
        "10"
    ), 
    array(
        "10", 
        "10"
    ), 
    array(
        "8", 
        "10"
    ), 
    array(
        "7", 
        "10"
    ), 
    array(
        "6", 
        "10"
    ), 
    array(
        "5", 
        "10"
    ), 
    array(
        "9", 
        "10"
    ) 
)

I need a function that will get me these four members:

array(“10”, “10”), array(“9”, “10”), array(“8”, “10”), array(“7”,
“10”)

Can anyone help?

Answer 1

Sort the array via usort() in descending order.
Pick the first four items via array_slice

<?php
$ar = getData();
usort( $ar, function($a,$b) { return -strnatcmp($a[0], $b[0]); });
$result = array_slice($ar, 0, 4);
var_dump($result);

function getData() {
    return array(
        array("1", "10"),
        array("9", "10"),
        array("3", "10"),
        array("4", "10"),
        array("10", "10"),
        array("8", "10"),
        array("7", "10"),
        array("6", "10"),
        array("5", "10"),
    );
}

prints

array(4) {
  [0]=>
  array(2) {
    [0]=>
    string(2) "10"
    [1]=>
    string(2) "10"
  }
  [1]=>
  array(2) {
    [0]=>
    string(1) "9"
    [1]=>
    string(2) "10"
  }
  [2]=>
  array(2) {
    [0]=>
    string(1) "8"
    [1]=>
    string(2) "10"
  }
  [3]=>
  array(2) {
    [0]=>
    string(1) "7"
    [1]=>
    string(2) "10"
  }
}