Split array and sort

Question

I have an array as follows:

'Ato001_1981',
'Ato002_1980',
'Ato003_1982',
'Ato003_1983',
'Ato004_1982',
'Ato013_1981',
'Ato013_1982',
'Ato013_1988',
'Ato031_1982',
'Ato032_1979',
'Ato039_1988',
'Ato060_1987',
'Ato065_1988',
'Ato066_1988',
'Ato067_1988',
'Ato076_1987',
'Ato077_1988',
'Ato078_1988',
'Ato095_1987',
'Ato137_1987',
'Ato144_1987'

I would like to break each row of the array to take the name and the year and then sort as in the text below:

Ano     Tipo
1988    Ato078
1988    Ato077
1988    Ato067
1988    Ato066
1988    Ato065
1988    Ato039
1988    Ato013
1987    Ato144
1987    Ato137
1987    Ato095
1987    Ato076
1987    Ato060
1983    Ato003
1982    Ato031
1982    Ato013
1982    Ato004
1982    Ato003
1981    Ato013
1981    Ato001
1980    Ato002
1979    Ato032

I tried the code below, but without success:

$new = array();
foreach($texto as $item):
    $valor = explode('_', $item);
    $new['ano'] = $valor[1];
    $new['tipo'] = $valor[0];    
    print_r($new);    
endforeach;

Answer 1

$texto = array(
    'Ato001_1981',
    'Ato002_1980',
    'Ato003_1982',
    'Ato003_1983',
    'Ato004_1982',
    'Ato013_1981',
    'Ato013_1982',
    'Ato013_1988',
    'Ato031_1982',
    'Ato032_1979',
    'Ato039_1988',
    'Ato060_1987',
    'Ato065_1988',
    'Ato066_1988',
    'Ato067_1988',
    'Ato076_1987',
    'Ato077_1988',
    'Ato078_1988',
    'Ato095_1987',
    'Ato137_1987',
    'Ato144_1987'
);

$new = array();
foreach($texto as $item):
    $valor = explode('_', $item);
    $new = ['ano' => $valor[1], 'tipo' => $valor[0]];

    echo $new['ano'] . '  ' . $new['tipo'] . '<br />';
endforeach;

Here it worked like this.

Answer 2

In the most elegant way possible, let’s go to the solution:

Your array is as follows:

$dados = array(
    'Ato001_1981',
    'Ato002_1980',
    'Ato003_1982',
    'Ato003_1983',
    'Ato004_1982',
    'Ato013_1981',
    'Ato013_1982',
    'Ato013_1988',
    'Ato031_1982',
    'Ato032_1979',
    'Ato039_1988',
    'Ato060_1987',
    'Ato065_1988',
    'Ato066_1988',
    'Ato067_1988',
    'Ato076_1987',
    'Ato077_1988',
    'Ato078_1988',
    'Ato095_1987',
    'Ato137_1987',
    'Ato144_1987'
);

First let’s turn this array. I believe that the most appropriate function for this is using array_map, for variable scope protection and own functionality for generating arrays based on other.

$array = array_map(function ($value){
    return explode('_', $value);
}, $dados);

Later we will use usort, comparing the values of array, through a callback in order to order it.

usort($array, function ($v1, $v2)
{
    $diff = $v2[1] - $v1[1];

    if ($diff) return $diff;

    return strcmp($v2[0], $v1[0]);

});

And finally, we have the array - obtained with var_export.

array (
  0 => 
  array (
    0 => 'Ato078',
    1 => '1988',
  ),
  1 => 
  array (
    0 => 'Ato077',
    1 => '1988',
  ),
  2 => 
  array (
    0 => 'Ato067',
    1 => '1988',
  ),
  3 => 
  array (
    0 => 'Ato066',
    1 => '1988',
  ),
  4 => 
  array (
    0 => 'Ato065',
    1 => '1988',
  ),
  5 => 
  array (
    0 => 'Ato039',
    1 => '1988',
  ),
  6 => 
  array (
    0 => 'Ato013',
    1 => '1988',
  ),
  7 => 
  array (
    0 => 'Ato144',
    1 => '1987',
  ),
  8 => 
  array (
    0 => 'Ato137',
    1 => '1987',
  ),
  9 => 
  array (
    0 => 'Ato095',
    1 => '1987',
  ),
  10 => 
  array (
    0 => 'Ato076',
    1 => '1987',
  ),
  11 => 
  array (
    0 => 'Ato060',
    1 => '1987',
  ),
  12 => 
  array (
    0 => 'Ato003',
    1 => '1983',
  ),
  13 => 
  array (
    0 => 'Ato031',
    1 => '1982',
  ),
  14 => 
  array (
    0 => 'Ato013',
    1 => '1982',
  ),
  15 => 
  array (
    0 => 'Ato004',
    1 => '1982',
  ),
  16 => 
  array (
    0 => 'Ato003',
    1 => '1982',
  ),
  17 => 
  array (
    0 => 'Ato013',
    1 => '1981',
  ),
  18 => 
  array (
    0 => 'Ato001',
    1 => '1981',
  ),
  19 => 
  array (
    0 => 'Ato002',
    1 => '1980',
  ),
  20 => 
  array (
    0 => 'Ato032',
    1 => '1979',
  ),
)

Answer 3

The least bad way to sort the key-based array is to use usort()

function cmp($a, $b) {
    return $a["ano"] < $b["ano"];
}


$texto = ['Ato001_1981','Ato002_1980','Ato003_1982','Ato003_1983','Ato004_1982','Ato013_1981'];

$new = array();
$index  = 0;
foreach($texto as $item){
    $valor = explode('_', $item);
    $new[$index]['tipo'] = $valor[0];
    $new[$index]['ano'] = $valor[1];
    $index++;
}

usort($new, "cmp");

echo '<pre>';
print_r($new);

Refrencia: Soen - Sort php multidimensional array by sub-value