<?php
 $testArray = array("value1", "value2");
 array_push($testArray, "value3", "value4");
 print_r($testArray);
 //rray ( [0] => value1 [1] => value2 [2] => value3 [3] => value4 )
?>

<?php
 $testArray = array(0 => 'value1', 1 => 'value4', 2 => 'value2', 3 => 'value3');
 $key = array_search('value2', $testArray); // $key = 2;
 echo "Key is ".$key ; // 2
?>

<?php
 $testArray = array(3, 2, 4, 7);
 echo "product is " . array_product($testArray);
 // product is 168
?>

<?php
 $testArray = array("orange", "banana", "apple", "raspberry");
 $replaceArr1 = array(0 => "pineapple", 3 => "cherry");
 $replaceArr2 = array(0 => "grape");
 $basket = array_replace($testArray, $replaceArr1, $replaceArr2);
 print_r($basket);
 //Array ( [0] => grape [1] => banana [2] => apple [3] => cherry )
?>

<?php
 $testArray1 = array("key1" => "val1", "key2" => "val2", "val4");
 $testArray2 = array("key4" => "val3", "val2", "val7");
 $testArray3 = array_diff($testArray1, $testArray2);
 print_r($testArray3);// Array ( [key1] => val1 [0] => val4 )
?>

<?php
 $testArray = array_fill(5, 3, 'Value1');
 print_r($testArray);
 //Array ( [5] => Value1 [6] => Value1 [7] => Value1 )
?>

<?php
 $testArray = array(12, 10, 9);
 print_r( array_pad($testArray, 6, 0));
 //  Array ( [0] => 12 [1] => 10 [2] => 9 [3] => 0 [4] => 0 [5] => 0 )
?>

<?php
 $testArray = array('foot', 'bike', 'car', 'plane');
 next($testArray);  next($testArray);
 echo prev($testArray); // bike
?>

<?php
 $testArray = array('foot', 'bike', 'car', 'plane');
 echo current($testArray);    // foot
?>

<?php
 $testArray = array('foot', 'bike', 'car', 'plane');
 secho next($testArray);    // bike
?>