Sorting Elements of an Array by number in string? - php

Question

I have a .txt file that looks like this:
john 1000
mike 8393
tom 1000
bob 233
roger 2
daniel 233
... ...
I need to put every line into array and sort by number size without losing what name goes with what number.
Also some numbers are repeating through the file.
Finally I want to echo elements of an array sorted by number size.

Answer 1

You could break each line into an array of integers and strings (split your current strings on the space) and then sort the array using ksort (assuming the key is the integer) and there you go!
You can of course alternatively use a more robust sort, but this will get you there.
You can then print it by using print_r to print the human readable version of the array
http://php.net/manual/en/array.sorting.php
http://php.net/manual/en/function.print-r.php

Answer 2

If you're running php 5.3+
$fileLines = explode("\n", $fileContents);
usort($fileLines, function($a, $b) {
$aNumber = (int)substr($a, strpos($a, ' ')+1);
$bNumber = (int)substr($b, strpos($b, ' ')+1);
if($aNumber === $bNumber) {
return 0;
}
return $aNumber > $bNumber ? 1 : -1;
});
If you're running a lower version, convert the function into a global function and provide the name as a callback string.
usort($fileLines, 'sortlines');
function sortlines($a, $b) {
$aNumber = (int)substr($a, strpos($a, ' ')+1);
$bNumber = (int)substr($b, strpos($b, ' ')+1);
if($aNumber === $bNumber) {
return 0;
}
return $aNumber > $bNumber ? 1 : -1;
}
then
var_dump($fileLines);

Answer 3

You can go three ways:
1.Create two-dimensional array with numeric indexes and sort it with usort(); and lambda function
$list = array(array('name' => 'john', 'number' => 1000),
array('name' => 'mike', 'number' => 8393),
array('name' => 'tom', 'number' => 1000)
);
$by = 'number';
usort($list, function($first, $second) use ($by)
{
if ($first[$by] > $second[$by] { return 1; }
elseif (first[$by] < $second[$by]) { return -1; }
return 0;
}
);
2.Create array with indexes as names and sort it with sort();
$list = array('john' => 1000,
'mike' => 8393,
'tom' => 1000
);
sort($list);
3.Create array with indexes as numbers and sort it with ksort();
$list = array(1000 => 'john',
8393 => 'mike',
1000 => 'tom'
);
ksort($list);
If you choose first way you can address the element as
$list[0][name] = 'bob'
$list[1][number] = 1000;
Second
$list['john'] = 1001;
Third
$list[1000] = 'bob';
In last two ways you should use foreach to go through array
Use
print_r($list);
or
var_dump($list);
to print the array, or create your own code
P.S. Don't forget thar calling usort with lambda function is PHP 5.3 way, if you use earlier version of PHP, you should use discrete function