<?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
?>

<?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 )
?>