PHP - How to sort the same array multiple times?

Question

I am trying to make a simple script that will first put an array() into function so I can call on it multiple times to sort. Here is what my array looks like:

// I want this inside of a function so I can call on it:

$a = array(
    15 => "C",
    12 => "E",
    11 => "B",
    19 => "P",
    10 => "L",
    14 => "N",
    20 => "A"    
 );

// This is how I brought it into a function and formatted it:

function original_array($a){ 
    foreach($a as $key => $types) {
        print $key . " " . ":" . " " . $types . "<br />";
    }
}

I then just have to call original_array() and it prints out fine, but if I sort it once I cant sort it again. It will just print out the first sort:

// Print out array is is:

original_array();

// Then I print out array with sort():

sort($a);
original_array($a);

// But if I try and sort it again with different sort it doesn't work:

ksort($a);
original_array($a);

What am I doing wrong? I am somewhat new to PHP so your help is greatly appreciated.

UPDATE://

This is what I ended up doing. I should have read up on sort function a little more thoroughly. I was unaware that it destroyed the original pointers.

<?php  
// Original array: 
$a = array(
    15 => "C",
    12 => "E",
    11 => "B",
    19 => "P",
    10 => "L",
    14 => "N",
    20 => "A"   
);

// Array for sort() function:
$b = $a

function print_format($array){ 
    foreach($array as $key => $types) {
        print $key . " " . "=>" . " " . $types . "<br />";
    }
}    


print "Original";  
print_format($a);     

print "sort()";
sort($b);
print_format($b);

print "ksort()";
ksort($a);
print_format($a);    

print "asort()";
asort($a);  
print_format($a);    

print "krsort()";
krsort($a);  
print_format($a);

print "rsort()";
rsort($b);  
print_format($b);    

print "arsort()";
arsort($a);  
print_format($a);
?>

animuson · Accepted Answer · 2012-03-23 00:52:21Z

4

The normal sort() function destroys the keys for all values, so when it's sorted, each key is now numeric 0, 1, 2, 3. Therefore when you use ksort(), it does nothing because they're already numerically sorted by key.

Try using asort() to maintain key => value association when sorting by value. Then when you use ksort() later on, the keys still exist so you can sort in that way.

answered Mar 23, 2012 at 0:52

animuson♦

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1 Comment

Derek Gutierrez Over a year ago

This helped immensely. sort() function through me off. I didn't understand why the others were working but they wouldn't if sort() was before them.

Huseyin · Accepted Answer · 2012-03-23 00:54:25Z

-1

You can use reset() function. http://php.net/manual/en/function.reset.php

answered Mar 23, 2012 at 0:54

Huseyin

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4 Comments

Derek Gutierrez Over a year ago

I have tried the reset. It may of been where I placed it, but it did not work.

Huseyin Over a year ago

my answer is signed as unused by someone. But I offered my option only. Can you use $b=$a; and after each sort($b) call $a again with ($b=$a) therefore $a will be remained as before.

Derek Gutierrez Over a year ago

That worked perfectly! So by assigning it to a new variable as stated ($b = $a) basically creates a new array that is unmodified?

Huseyin Over a year ago

Ok. But I loosed some points because of negative pointing. Please accept mine answer.

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