Multiply an entire array by some value

[Krentenbol]

I want to multiply an array by some value, in this case it's 1.5. I wrote this:

PHP Code:

<?php
$array = array(1000, 2000, 2500, 1500);
$i = 0;
while ($i < 4) {
    $array[$i] = $array[$i] * 1.5;
    echo "$array[$i] <br />";
    $i++;
}
?>

Is this the easiest way or is there some function which allows me to just multiply $array with some value. Since if I try this:

PHP Code:

$array = $array * 1.5; 


It throws out this error:

Fatal error: Unsupported operand types

[jmj001]

afaik the loop is the easiest way

you could easily create your own function with that loop

PHP Code:

<?php


$array = array(1000, 2000, 2500, 1500);
$newArray = inc_my_array_vals($array,1.5);


function inc_my_array_vals($arr,$incVal){
    $newArr = array();
     $j = count($arr);
     for($i = 0; $i < $j; $i++){
        $newArr[$i] = $arr[$i] * incVal;
      }

     return $newArr;
}
?>

[tangoforce]

PHP Code:

<?php
function multiply(&$Value, $Index, $By) //Note & character - means passed by reference
   {
   $Value = ($Value * $By);
   }

$array = array(1000, 2000, 2500, 1500); 

array_walk($array, 'multiply', 1.5);

var_dump($array);
?>

You can see it in action here.

[Fou-Lu]

No, you can also use an array_walk:

PHP Code:

function multiplyByX(&$val, $key, $dMult)
{
    $val *= $dMult;
}

$array = array(1000, 2000, 2500, 1500); 
array_walk($array, 'multiplyByX', 1.5);
print_r($array); 


Not much different code wise between writing a function to multiply and writing a function for the walk. Only thing you don't need to do is loop since that's handled under the hood instead.

Edit:
Nooo too slow this time >.<
lol

[tangoforce]

Originally Posted by Fou-Lu

Edit:
Nooo too slow this time >.<
lol

Muhahaha

[abduraooft]

PHP Code:

<?php
$array = array(1000, 2000, 2500, 1500); 
function multiply($elm){
    return $elm * 2;
}
$array=array_map('multiply',$array);
print_r($array);
?>

[Krentenbol]

Hmm several methods to use, I'll look which one is best in performance. Thank you all.