Print Array

$clients = ["Client_A", "Client_B", 1, 2];
var_dump ($clients);
print_r ($clients);

Print Array Elements

$clients = ["Client_A", "Client_B", 1, 2];
echo $clients[0];
echo $clients[1];
echo "$clients[2]";
echo $clients[3];

Array Length

$clients = ["Client_A", "Client_B", 1, 2];
echo count($clients);

Print Array Using for Loop

$clients = ["Client_A", "Client_B", 1, 2];
$totalCount = count($clients);
for ($i = 0; $i <= $totalCount; $i++) {
      echo $clients[$i];
}

Print Array Using foreach Loop

$clients = ["Client_A", "Client_B", 1, 2];
foreach ($clients as $c) {
      echo $c;
}

Adding New Element To An Existing Array

$clients = ["Client_A", "Client_B", 1, 2];
$clients[] = "New Client"; // adding new element to an existing array
foreach ($clients as $c) {
      echo $c;
}

Associative (key => value) Array

$clients = [
      1 => "Client_A",
      2 => "Client_B",
      3 => "Client_C"
      ];

foreach ($clients as $key => $value) {
      echo $key . " => " . $value; // key and value are just variables, name those as you would like.
}

$months = [
      "JAN" => "January",
      "FEB" => "February",
      "MAR" => "March"
      ];

foreach ($months as $key => $value) {
      echo $key . " => " . $value; // key and value are just variables, name those as you would like.
}

Acces Array Keys Only

$months = [
      "JAN" => "January",
      "FEB" => "February",
      "MAR" => "March"
      ];

foreach (array_keys($months) as $keys) {
      echo $keys;
}

Acces Array Values Only

$months = [
      "JAN" => "January",
      "FEB" => "February",
      "MAR" => "March"
      ];

foreach ($months as $m) {
      echo $m;
}

Acces value by a specific key

$months = [
      "JAN" => "January",
      "FEB" => "February",
      "MAR" => "March"
      ];

echo $months["FEB"];

Adding A New Element In An Associative Array

$months = [
      "JAN" => "January",
      "FEB" => "February",
      "MAR" => "March"
      ];

$months["APR"] = "April";
echo $months["APR"];

Multidimensional Array (array(s) inside an array)

$clientIds = [
            [1, 2, 3],
            [100, 200, 300]
      ];

foreach ($clientIds as $ids) {
      echo "--- Client Ids ---";
      foreach ($ids as $id) {
            echo $id;
      }      
}

$clientIds = [
            1 => [10, 100, 1000],
            2 => [20, 200, 2000]
      ];

foreach ($clientIds> as $key => $value) {
      echo "--- $key ---";
      foreach ($value as $val) {
            echo $val;
      }      
}

Removing Element From An Array

$Ids = [1, 2, 3];
echo "Array Length: " . count($Ids);
unset($Ids[2]); // removing last element from the array
echo "Array Length: " . count($Ids);

$Ids = [4]; // adding new element
for ($i=0; $i <= count($Ids); $i++) {
      echo $Ids[$i];
}      

Sorting Arrays Ascending

$clientIds = [5, 4, 1, 3, 2];
sort($clientIds);
foreach ($clientIds as $id) {
      echo $Ids[$id];
}      

Sorting Associative Arrays Ascending

$planets = [
            2 => "Mars",
            1 => "Earth",
            3 => "Jupitor"      
      ];

asort($planets);
foreach ($planets as $planet) {
      echo $planet;
}      

Sorting Associative Array Keys Ascending

$planets = [
            2 => "Mars",
            1 => "Earth",
            3 => "Jupitor"      
      ];
      
ksort($planets);
foreach ($planets as $planet) {
      echo $planet;
}      

Sorting Arrays Descending

$clientIds = [5, 4, 1, 3, 2];
rsort($clientIds);
foreach ($clientIds as $id) {
      echo $Ids[$id];
}      

Sorting Associative Arrays Descending

$planets = [
            2 => "Mars",
            1 => "Earth",
            3 => "Jupitor"      
      ];

arsort($planets);
foreach ($planets as $planet) {
      echo $planet;
}      

Sorting Associative Array Keys Descending

$planets = [
            2 => "Mars",
            1 => "Earth",
            3 => "Jupitor"      
      ];
      
krsort($planets);
foreach ($planets as $planet) {
      echo $planet;
}      

Copying Array

$months = ["January", "February", "March"];
$monthsCopied = $months;
foreach ($monthsCopied as $mc) {
      echo $mc;
}      

$months = ["January", "February", "March"];
foreach ($monthsCopied as $mc) {
      if($mc == "January" || $mc == "February") {
            $monthsCopied[] = $months;
      }
}
foreach ($monthsCopied as $mc) {
      echo $mc;
}      

Split Array

$months = "January, February, March";
$monthsArray = explode($months);

echo $months;
foreach ($monthsArray as $ma) {
      echo $ma;
}      

$months = "January, February, March";
$monthsArray = explode($months, 2);

echo count($months);
echo $months[0];
echo $months[1];

Convert Array To String

$monthsArray = ["January", "February", "March"];
$months = implode($monthsArray);

echo $months;