sizeof($arr) //returns the size of elements in the array
is_array($arr) // returns true if $arr is an array and false otherwise
in_array($var, $arr) // check if $var is in the array $arr
print_r($arr) // prints the complete representation of the array
array_merge($arr1, $arr2) //combines $arr1 and $arr2 into a single array
array_values($arr) //store all the values into a new array without the keys but only the values
array_keys($arr) // returns only the keys inside an array
array_pop($arr) // removes the last element of the array
array_push($arr, $val) // pushes $val to the end of array
array_shift($arr) // removes the first element in the array $arr
sort($arr) // sorts an array in an ascending order
/*Other sorting methods are:
-asort()
-arsort()
-ksort()
-krsort()
-rsort()
*/
array_map('function_name', $arr) // passes each value in the array inside the fuction and do the operation on the array data
array_flip($arr) //This function interchange the keys and the values of a PHP associative array.
array_reverse($arr) //This function is used to reverse the order of elements
array_rand($arr) //randomly pick an element from the array
array_slice($arr, $offset, $length)//This function is used to create a subset of any array