<?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
?>

<?php
 $testArray = array("key1" => "Value1","key2" => "Value2","key3" => "Value3");
 $testArray = array_flip($testArray);
 print_r($testArray);
 //Array ( [Value1] => key1 [Value2] => key2 [Value3] => key3 )
?>

<?php
 $testArray	= array(5, 3, 8, 10);
 echo  "Sum is : ".array_sum($testArray) ;
 //Sum is : 26
?>

<?php
 $search_array = array('key1' => 17, 'key2' => 74);
 if (array_key_exists('key1', $search_array)) {
    echo "The key 'key1' exists ";
 }
 //The key 'key1' exists
?>

<?php
 $testArray=array("Value1","Value1","Value1","Value2");
 print_r(array_count_values($testArray));
 //Array ( [Value1] => 3 [Value2] => 1 )
?>

<?php
 $testArray1 = array('key1', 'key2', 'key3');
 $testArray2 = array('value1', 'value2', 'value3');
 $testArray3 = array_combine($testArray1, $testArray2);
 print_r($testArray3);
 //Array ( [key1] => value1 [key2] => value2 [key3] => value3 )
 //  NOTE : Make sure that the 2 arrays have  equual 
 //  number of elements
?>

<?php
 $testArray1 = array("place" => "kochi", 11, 12);
 $testArray2 = array("p", "s", "place" => "Tvm", "Width" => "10", 84);
 $testArray3 = array_merge($testArray1, $testArray2);
 print_r($testArray3);
 //Array ( [place] => Tvm [0] => 11 [1] => 12 [2] => p [3] 
 //=> s [Width] => 10 [4] => 84 )
?>

<?php
 $testArray = array("Value1","Value2", "Value3");
 print_r(array_map('strtoupper', $testArray));
 // Array ( [0] => VALUE1 [1] => VALUE2 [2] => VALUE3 )
?>