Array Function

1.count : The function returns the number of elements in an array.

Syntax: int count(array);
<?php
$cars=array("Volvo","BMW","Toyota");
echo count($cars); //3
?>

2. list : The function is used to assign values to a list of variables in one operation.

Syntax: list(var1,var2...)

    <?php
          $my_array = array("Dog","Cat","Horse");
            list($a, $b, $c) = $my_array;
           echo "I have several animals, a $a, a $b and a $c.";
       ?>

        Output: I have several animals, a Dog, a Cat and a Horse. 

3.  In_array : The in_array() function searches an array for a specific value. This function returns TRUE if the value is found in the array, or FALSE otherwise.

Syntax: in_array(search,array)

<?php

$fruit = array("mango", "apple", "banana", "grapes");

 if (in_array("grapes",$fruit))

{

echo "Match found";                           //match found

}

else

{

echo "Match not found";

}

?>

4.  current : The current() function returns the value of the current element in an array.

Syntax: current(array)

5.   next : The next() function moves the internal pointer to, and outputs, the next element in the array.

Syntax: next(array)

6.   prev: The prev() function moves the internal pointer to, and outputs, the previous element in the array.

Syntax: prev(array)

7.    end: The end() function moves the internal pointer to, and outputs, the last element in the array.

   <?php
          $cars=array("Volvo","BMW","Toyota");
          echo current($cars) . "<br />"; //Volvo
          echo next($cars)."<br />"; //BMW
          echo prev($cars)."<br />";//Volvo
          echo end($cars) . "<br />";//Toyota
   ?> 

8.  each : The each() function returns the current element key and value, and moves the internal pointer forward. This element key an value is returned in an array with four elements. Two elements (1 and Value) for the element value, and two elements (0 and Key) for the element key.

Syntax: array each(array);

   <?php
       $cars=array("Volvo","BMW","Toyota");
         print_r (each($people));
   ?>
      Output: Array ( [1] => Volvo [value] => Volvo [0] => 0 [key] => 0 )

9.  sort : The sort() function sorts an indexed array in ascending order.

Syntax: sort(array);

10.  rsort: The rsort() function sorts an indexed array in descending orde

Syntax: sort(array);

11.  asort : The asort() function sorts an associative array in ascending order, according to the value.

Syntax:asort(array);

12.   arsort : The asort() function sorts an associative array in ascending order, according to the value.

Syntax:arsort(array);

   <?php
      $cars=array("Volvo","BMW","Toyota");
       sort($cars);
       print_r($cars);//Array ( [0] => BMW [1] => Toyota [2] => Volvo )
       rsort($cars);
        print_r($cars);// Array ( [0] => Volvo [1] => Toyota [2] => BMW )
        asort($cars);
        print_r($cars);// Array ( [1] => BMW [2] => Toyota [0] => Volvo )
        arsort($cars);
        print_r($cars);// Array ( [0] => Volvo [2] => Toyota [1] => BMW )
?>

13.   array_merge: The array_merge() function merges one or more arrays into one array.

Syntax: array_merge(array1,array2,array3...)

     <?php
       $cars=array("Volvo","BMW","Toyota");
       $byk=array(“pulser”,”r15”,”karizma”);
       $a= array_merge($cars,$byk); Print_r($a);
     ?>
Output: Array ( [0] => Volvo [1] => BMW [2] => Toyota [3] => pulser [4] => r15 [5] => karizma )

14.   array_reverse: The array_reverse() function returns an array in the reverseorder.

Syntax: array_reverse(array)

<?php

$cars=array("Volvo","BMW","Toyota");

print_r(array_reverse($cars));    Array ( [0] => Toyota [1] => BMW [2] => Volvo )

?>

15.   array_diff: This function compares the values of two (or more) arrays, and return an array that contains time.
<?php
$a1=array("a"=>"red","b"=>"green","c"=>"blue","d"=>"yellow");
$a2=array("e"=>"red","f"=>"green","g"=>"blue");
$result=array_diff($a1,$a2);
print_r($result);//Array ( [d] => yellow )
?>.

Syntax: array_diff(array1,array2,array3...);   

16.   array_merge_recursive: it merges the elements of one or more arrays together so that the values of one are appended to the end of the previous one. It returns the resulting array.

           <?php
                 $a1 = array('first'=>'bob', 'last'=>'jones', 'age'=>'48');
                 $a2 = array('first'=>'sam', 'last'=>'smith', 'age'=>'41');
                 $a3 = array('first'=>'pete', 'last'=>null, 'age'=>'3');
                $a4 = array('first'=>'joe', 'last'=>'johnson', 'age'=>'33');
               $a5 = array_merge_recursive($a1,$a2,$a3,$a4); print_r($a5);
          ?>

Output:
Array (
[first] => Array (
[0] => bob
[1] => sam
[2] => pete
[3] => joe
)
[last] => Array (
[0] => jones
[1] => smith [2] =>
[3] => johnson
)
[age] => Array (
[0] => 48
[1] => 41
[2] => 3
[3] => 33

)

)
Syntax: array array_merge_recursive (array1,array2,array3...);

 

          17.  array_shift: The array_shift() function removes the first element from an array, and returns the value of the removed element.

Syntax: array_shift(array)

   <?php
            $cars=array("Volvo","BMW","Toyota"); array_shift($cars);
            print_r($cars); //Array ( [0] => BMW [1] => Toyota );
    ?>       

          18.   array_slice: The array_slice() function returns selected parts of an array.

  Syntax: array_slice(array,start)

<?php
$a=array(0=>"Dog",1=>"Cat",2=>"Horse",3=>"Bird");
print_r(array_slice($a,1)); //Array ( [0] => Cat [1] => Horse [2] => Bird )
?>

    

19.   array_unique: The array_unique() function removes duplicate values from an array. If two or more array values are the same, the first appearance will be kept and the other will be removed.

Syntax: array_unique(array)

       <?php
           $a=array("a"=>"Cat","b"=>"Dog","c"=>"Cat");
           print_r(array_unique($a));   // Array ( [a] => Cat [b] => Dog )

         ?>

20.  array_unshift: The array_unshift() function inserts new elements to an array. The new array values will be inserted in the beginning of the array

Syntax: array_unshift(array,value1,value2,value3...)

21.  array_push: The array_push() function inserts one or more elements to the end of an array.

Syntax: array_push(array,value1,value2...)

22.  array_pop: The array_pop() function deletes the last element of an array.

Syntax: array_pop(array)

       <?php

            $a=array("a"=>"Cat","b"=>"Dog");
           array_unshift($a,"Horse");
           print_r($a); // Array ( [0] => Horse [a] => Cat [b] => Dog ) array_push ($a,"sparrow","Bird");
           print_r($a); //Array ( [0] => Horse [a] => Cat [b] => Dog [1] => sparrow [2] => Bird )
           array_pop ($a);
           print_r($a); //Array ( [0] => Horse [a] => Cat [b] => Dog [1] => sparrow )

?>

23.  array_keys: The array_keys() function returns an array containing the keys.

Syntax: array_keys(array)

          <?php

            $a=array(0=>"Dog",1=>"Cat",2=>"Horse",3=>"Bird");
           print_r(array_keys($a));// Array ( [0] => 0 [1] => 1 [2] => 2 [3] => 3 )

         ?>

24.  array_key_exists: The array_key_exists() function checks an array for a specified key, and returns true if the key exists and false if the key does not exist.

Syntax: array_key_exists(key,array)

          <?php
              $a=array("a"=>"Dog","b"=>"Cat");
               if (array_key_exists("a",$a))
             echo "Key exists!";         //key exists!
              else
                 echo "Key does not exist!";
            ?>

25. array_multisort: The array_multisort() function returns a sorted array. You can assign one or more 

arrays. The function sorts the first array, and the other arrays follow, then, if two or more values are the same, it sorts the next array, and so on.

Syntax: array_multisort(array1, array2,array3...)

     

        <?php

$a1=array("d","C");

$a2=array("b","h"); array_multisort($a1,$a2);

print_r($a1); //Array ( [0] => b [1] => d ) print_r($a2); //Array ( [0] => c [1] => d )

        ?>
        26.array_search: The array_search() function search an array for a value and returns the key.
Syntax: array_search(value,array)
<?php
$a=array("a"=>"Dog","b"=>"Cat","c"=>"Horse");
echo array_search("Dog",$a);      //a
?>