PHP Rotate and adding to an array

Question

Is it possible to do something like the following in PHO

I return an array from my DB that looks like the following

1, 2 ,3 now i want to add a forth number to it and then resort them so

1 becomes 5
2 becomes 1
3 becomes 2
Fourth Number becomes 3

or is there a away to rearrange my table so it rotates. What i am trying to do is rotate and return a row in the database in order but once it has been returned i want to my page i want to get a user to enter another row into my database and then put the row that had been returned to the end so it would have the highest value.

I am basically updating my column by subtracting one from all entries and increaseing my first entry to the highest number

a. 1,2,3
b. 4,1,2,3
c. 3,5,1,2,4
d. 2,4,6,1,3,5

Hmmmm I dont think what i am saying is exacty what i am looking for or maybe someone understands what i am trying to say so i wont change it.

Or if i could use a auto incremented key starting at 1 and just rearrange all the data in the other columns would work.

So do this 1. Count the number of row 2. Return an array with all database table entries 2. Add a new entry to the database on the last row. 3. Move the entry in 1 to the number of rows +1 (creating a new row 4. Move all other entries up one.

so here is is

1 -> a
2 -> b
3 -> c

after adding another row

1 -> b
2 -> c
3 -> d
4 -> a

After adding another row

1 -> c 
2 -> d 
3 -> a 
4 -> e
5 -> b

After adding another row

1 -> d
2 -> a
3 -> e
4 -> b
5 -> f
5 -> c

After adding another row

1 -> a
2 -> e
3 -> b
4 -> f
5 -> c
5 -> g
5 -> d

WHO can come up with a solution for me?????

how about explaining the big picture, i would bet there is a better approach — user557846
– user557846, Commented Oct 29, 2012 at 8:06

Abhishek Saha · Accepted Answer · 2012-10-29 21:52:48Z

0

You can use the below function and pass the shifting parameter to it. The function name is rotate_array() below. After using the function add the next value.

<?php

$weekdays = array("Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun");

function rotate_array($steps, $arr)
{
    if($steps >= 0)
    {
        for($i = 0; $i < $steps; $i++)
        {
            $elm = array_shift($arr);
            array_push($arr, $elm);
        }
    }
    else
    {
        for($i = 0; $i > $steps; $i--)
        {
            $elm = array_pop($arr);
            array_unshift($arr, $elm);
        }
    }
    return $arr;
}

$arr = rotate_array(1, $weekdays);

//For multidimensional array, add this part

foreach($arr as $key => $childArray) {

       rotate_array(1,$childArray);


}
//end of addition

$arr[] = "next value";
echo "<pre>";
print_r($arr);
echo "</pre>";


?>

Output:

Array
(
    [0] => Tue
    [1] => Wed
    [2] => Thu
    [3] => Fri
    [4] => Sat
    [5] => Sun
    [6] => Mon
    [7] => next value
)

edited Oct 29, 2012 at 21:52

answered Oct 29, 2012 at 8:10

Abhishek Saha

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2 Comments

Kieron Garvey Over a year ago

I edited this a little and it now works great for a single array but how do i do the same with a multi demensional array and keep all the data intact.

Abhishek Saha Over a year ago

added some codes. Read my comments for multidimensional array.

air4x · Accepted Answer · 2012-10-29 08:36:47Z

0

Try

$arr = array('a','b','c');
$value = 'd';
$arr = my_sort($arr, $value);
print_r($arr);
echo nl2br(PHP_EOL);
$arr = my_sort($arr, 'e');
print_r($arr);

function my_sort($arr, $value) {
  $arr[] = $value;
  $first = array_shift($arr);
  $arr[] = $first;

  return $arr;
}

Check http://codepad.viper-7.com/yJE8FR

edited Oct 29, 2012 at 8:36

answered Oct 29, 2012 at 8:08

air4x

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1 Comment

Kieron Garvey Over a year ago

How would i use your method with a mutli demensional array returned from a database and then updating the database when finished.Table name : Rotator Columns: ID(Auto increament), fb_user_id, frist_name, email, link_url, referred_by, signups, order Order is the entry that i would like to rotate and fb_user_id is always going to be unique

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