CODEWITHSUNDEEP
phparrayssortingcsv
jiggers
jiggers

Reputation: 23

How do I sort an Array with comma separated strings in PHP?

it's my first post here, I'm a beginner and I hope you'll go easy on me. I searched for an answer, and read some semi-related questions. I've been stuck on this for a couple days and I really am very confused. Apologies if the double barrelled is a faux pas, it seemed less sensible to write this as two seperate questions. I'm new to programming and I had never heard of this website until yesterday, I hope to be a contributing part of what seems to be an awesome community.

I have an array, $newarray:

Array
(
    [2] => string1,10
    [7] => string2,15
    [10] => string3,3
    [11] => string4,7
)

I'm able to write it to a CSV file, and so far so good:

<?php
    $file = fopen("/myfile.csv","w");
    foreach ($newarray as $line)
      {
        fputcsv($file,explode(',',$line));
      }
    fclose($file);
?>

However, I'm trying to do two things.

  1. Sorting the array by reverse order of the numerical values before writing to CSV, so I would have a CSV file as so:

    string2,15
string1,10
string4,7
string3,3

  2. Create a second file (after writing the first CSV), where the numerical values are stripped out, as so:

    string2
string1
string4
string3

Can someone steer me in the right direction?

Upvotes: 2

Views: 1585

Answers (4)

Professor Abronsius
Professor Abronsius

Reputation: 33813

$a=array(/* Original array */
    2   =>  'string1,10',
    7   =>  'string2,15',
    10  =>  'string4,3',
    11  =>  'string4,7'
);      

$c=array();
foreach( $a as $index => $value ){
    list($s,$i)=explode(',', $value );
    $c[$i]=$value;
}
/* Sort in reverse order */
krsort($c);

/* The value of $c is then written to your csv */

/* callback function to get the string */
function cb(&$item,$key){
    list( $s,$i )=explode(',',$item );
    $item=$s;
}
array_walk( $c, 'cb' );

echo '<pre>',print_r($b,true),'</pre>';

Upvotes: 0

miglio
miglio

Reputation: 2058

$arraybase = array(
    2 => 'string1,10',
    7 => 'string2,15',
    10 => 'string3,3',
    11 => 'string4,7',
);
function mapping($data){
    $array1 = array();//for first csv
    array_walk($data,function($value,$key)use(&$array1){
        $k=explode(',',$value);
        $array1[$k[1]] = $value;
    });
    krsort($array1);
    $array2 = array_map(function($value){//for second csv
        return preg_replace('/,\d+$/','',$value);
    },$array1);

    return array("csv1"=>$array1,"csv2"=>$array2);
}
$result = mapping($arraybase);
print('<pre>');print_r($result);

output:

Array
(
    [csv1] => Array
        (
            [15] => string2,15
            [10] => string1,10
            [7] => string4,7
            [3] => string3,3
        )

    [csv2] => Array
        (
            [15] => string2
            [10] => string1
            [7] => string4
            [3] => string3
        )

)

Upvotes: 1

Jeffwa
Jeffwa

Reputation: 1143

Does your $newArray have to have concatinated values? If not, it's better to have them as sub-arrays:

$newArray = array (
    2 => array(
        0 => 'string1',
        1 => 10,
    ),
    7 => array(
        0 => 'string2',
        1 => 15,
    ),
    10 => array(
        0 => 'string3',
        1 => 3,
    ),
    11 => array(
        0 => 'string4',
        1 => 7,
    ),
);

Then you can sort using array_multisort:

$strings = array();
$numbers = array();
foreach ($newArray as $key => $row) {
    $strings[$key]  = $row[0];
    $numbers[$key] = $row[1];
}

array_multisort($numbers, SORT_DESC, $strings, SORT_ASC, $newArray);

When you write to the CSV:

<?php
    $file = fopen("/myfile.csv","w");
    foreach ($newArray as $line) {
        fputcsv($file, $line); // No need to explode as your data ia already in an array
    }
    fclose($file);
?>

To write to a second CSV with just the strings:

<?php
    reset($newArray); // Sets the pointer in the array back to the beginning so it can be looped over again
    $file = fopen("/myfile2.csv","w");
    foreach ($newArray as $line) {
        fputcsv($file, $line[0]);
    }
    fclose($file);
?>

Upvotes: 1

Ulrik Pedersen
Ulrik Pedersen

Reputation: 73

For your first question try http://php.net/manual/en/function.rsort.php and give it at shot :)

Upvotes: 0

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