nikic

Why objects (usually) use less memory than arrays in PHP

This is just a small post in response to [this tweet][tweet] by Julien Pauli (who by the way is the release manager for PHP 5.5). In the tweet he claims that objects use more memory than arrays in PHP. Even though it can be like that, it's not true in most cases. (Note: This only applies to PHP 5.4 or newer.)

The reason why it's easy to assume that objects are larger than arrays is because objects can be seen as an array of properties and a bit of additional information (like the class it belongs to). And as array + additional info > array it obviously follows that objects are larger. The thing is that in most cases PHP can optimize the array part of it away. So how does that work?

The key here is that objects usually have a predefined set of keys, whereas arrays don't:

ralt

tl;dr we're lazy, we're coders.

Let's make use of that.

• We don't like to start off new projects and write all the booooring boilerplate
• We like to fiddle with code and fix it
• We like recognition
• We're quickly bored

Hence, I present to you my idea:

CS1000

// ==UserScript==
// @name        JamExchange Player
// @namespace   jamexchange
// @description JamExchange Room @SO Live Radio like Player with "User Requests" (YoutTube only)
// @include     http://chat.stackoverflow.com/rooms/39426/*
// @version     1.1.0
// @grant       none
// ==/UserScript==

/*

morrisonlevi

<?php

define('ITERATIONS', 10000000);
$var = 0;

$start = microtime(true);
$var = 0;
while ($var < ITERATIONS) {
  ++$var;
}

hakre

Print_r Converter

As of September 2013, the repository has been moved from this Github Gist (hakre/1102761) over to a public Github repository in my account. You can find it now here:

• https://github.com/hakre/print_r-converter

Please visit that address for more information, updates and code.

CS1000

javascript:(function(){$(".answer").each(function(i,n){if(n.id!==('answer'+document.location.hash).replace(/#/,'-'))n.style.display="none"})})()

CS1000

function hashCode(str) {
    var hash = 0;
    str += '!';
    for (var i = 0; i < str.length; i++) {
        hash = str.charCodeAt(i) + ((hash << 5) - hash);
    }
    return -hash;
}
function colorCode(i) {
    return '#' + (Math.min((i >> 24) & 0xFF, 200).toString(16) +

CS1000

/*
* @param      rgb = Object {r, g, b}
* @param  percent = int (-100 to 100)
*/
function shadeColorTone(rgb, percent)
{
    perc = 1 + percent / 100;
    ret = {}
    Object.keys(rgb).map(function(v) {
        col = rgb[v];

CS1000

function setContrast(rgb, perc)
{
    ret = {}
    Object.keys(rgb).map(function(v) {
        col = rgb[v];
        if (perc <= 0) {
            col += (col - 128) * perc / 100; // ---> 128
        } else {
           if (col < 128) {
               //bad start

CS1000

function setContrast(rgb, perc)
{
    perc = perc / 100;
    ret = {}
    Object.keys(rgb).map(function(v) {
        col = rgb[v];
        if (perc <= 0) {
            col += (col - 128) * perc; // ---> 128
        } else {
           if (col < 128) {