Adding value to array without using loops

Question

I was wondering if it's possible to add a values to an array without using loops.

Yes, I know that technically I can write :

$myArray = array(0,2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32); //etc...

But as you can see on the example if the line is very long it's smarter to do it with a loop.

Now since I already know that each number will be raised by +2 I was wondering if there is internal php command right of the box so I can do it with a callback or any other magic trick ;)

Not the correct syntax but just so you can get the idea.

$myArray = Array();
$myArray[] = insertArray($valueOf{$x};$x;$x>=100;$x=+2);

Yea, I know that this can also applied as a function/class but I'm asking if I can do that magic RIGHT OF THE BOX :)

Thanks!

if you know that the sequence is 0,2,4,..... you don't need to store in array because you know ith number is 2*(i-1) ( 1 based index) — advocateofnone
– advocateofnone, Commented Jan 8, 2015 at 11:29

violator667 · Accepted Answer · 2015-01-08 11:28:48Z

5

You can create an array containing a range of elements using range() it supports skip parameter

$a = range(0,10,2);
print_r($a);

Array
(
    [0] => 0
    [1] => 2
    [2] => 4
    [3] => 6
    [4] => 8
    [5] => 10
)

answered Jan 8, 2015 at 11:28

violator667

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3 Comments

Rizier123 Over a year ago

Maybe you could add an example for OP, otherwise it's a nice answer

iprophesy Over a year ago

SUPERB! :)))))))))))))))))))))))))

Rizier123 Over a year ago

@iprophesy Please don't spam with smiles and so on also don't use caps! You can write something like: Thanks this worked for me or something like that

Praveen Kumar Purushothaman · Accepted Answer · 2015-01-08 11:29:14Z

2

Yes, you have something called array_walk. Define a function like this:

function addTwo (&$item, $key)
{
    $item = $item * 2;
}

Then use the function this way:

array_walk ($myArray, 'addTwo');

In your use case, you can either use range() with the skip option or, you can use this way:

array_walk (range (0, $max));

Or, with range():

range (0, $max, 2);

answered Jan 8, 2015 at 11:29

Praveen Kumar Purushothaman

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2 Comments

vaso123 Over a year ago

And how is this adding an element to an array?

Praveen Kumar Purushothaman Over a year ago

@violator667 Err... Yeah, fine. All possible ways I said.

Styphon · Accepted Answer · 2015-01-08 11:36:41Z

-1

You can do this with range() (PHP Manual). To produce your array do:

$array = range(0, 32, 2);

The last variable is the number of steps to make between each entry in the array. It defaults at one but by setting it to 2 each number will increment by 2.

print_r($array);

produces

Array
(
    [0] => 0
    [1] => 2
    [2] => 4
    [3] => 6
    [4] => 8
    [5] => 10
    [6] => 12
    [7] => 14
    [8] => 16
    [9] => 18
    [10] => 20
    [11] => 22
    [12] => 24
    [13] => 26
    [14] => 28
    [15] => 30
    [16] => 32
)

edited Jan 8, 2015 at 11:36

answered Jan 8, 2015 at 11:31

Styphon

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1 Comment

Styphon Over a year ago

And why a -1? This answers the OPs question.

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