How can I get the current array index in a foreach loop?

Question 1

How do I get the current index in a foreach loop?

foreach ($arr as $key => $val)
{
    // How do I get the index?
    // How do I get the first element in an associative array?
}

Question 2

In your sample code, it would just be $key.

If you want to know, for example, if this is the first, second, or i^th iteration of the loop, this is your only option:

$i = -1;
foreach($arr as $val) {
  $i++;
  //$i is now the index.  if $i == 0, then this is the first element.
  ...
}

Of course, this doesn't mean that $val == $arr[$i] because the array could be an associative array.

Question 3

The reason for the "overwriting" is $tempChild = $child;.

That will not deep copy the contents of $child but make both $tempChild and $child point towards the same data structure, which obviously isn't desirable in this case.

You should use clone as in the below example.

$tempChild = clone $child;

PHP: Object Cloning - Manual

Question 4

Comments included.

<?php

//Require Core Component
require_once("xyz.php");

$Threads = new StackableArray();

//A Global Storage that will be shared between threads.
$Storage = new Storage();

//Store {count} in Global Storage
$Storage['count'] = 0;


/*
 * For Each Site, spawn a new thread, process the site and store result in Global Storage.
 */
foreach($sites as $site)
{
    $Thread = new SiteProcess($Storage, $site);
    $Thread->start();
    $Threads[$re] = $Thread;
}

//When the threads are complete, join them(destroy the threads)
foreach($Threads as $Thread)
{
    $Thread->join();
}

//A thread class
class SiteProcess extends Threads
{
    private $Storage;
    private $site;

    public function __construct(Storage $Storage, $site)
    {
        $this->Storage = $Storage;
        $this->site = $site;
    }

    public function run()
    {
        require_once("allsite/{$this->site}.php");
        $siteObj = new $this->site;
        $this->Storage[$this->Storage['count']] = $siteObj->getsiteData($query, $cat);
        $this->Storage['count'] = $this->Storage['count'] + 1;
    }
}

class StackableArray extends Stackable { public function run() { } };

class Storage extends Stackable { public function run() { } };

Question 5

You can do something like this:

int i = 0;
foreach (var grouping in Class.Students.GroupBy(s => ++i / 20))
    Console.WriteLine("You belong to Group " + grouping.Key.ToString());

Question 6

In OS 3.x, there's a property called "zoomScale" that will give you what you want. In 2.x, I believe you can look directly at the contentView's transform to obtain this (but that is, of course, not 'official'.)

How can I get the current array index in a foreach loop?

Answers

php,syntax,foreach